Now that you know you are pregnant, one of the first things you want to ask your doctor is, “how many weeks pregnant am I?” Knowing the exact age of your growing baby depends on a few different things and the information below can help understand the very early weeks of pregnancy. The included chart can help you understand the different weeks, months and trimesters of pregnancy.

How Many Weeks Pregnant Am I?

image001Since it is nearly impossible to know the exact day that your ovaries released an egg and you conceived, doctors cannot accurately count the weeks of pregnancy from the estimated date of conception. In order to count the approximate weeks of pregnancy you will need to know the first day of your last menstrual period. Pregnancy due dates are counted 40 weeks from the first day of your last period.

For example, if you are pregnant and it’s been 21 days from the first day of your last menstruation, then you are 3 weeks pregnant, even thought it may be less than 3 weeks that your baby has developed in you because you can only get pregnant after you ovulate, which would be around day 14 of your menstrual period.

Here is a list of answers to the most common questions about calculating pregnancy and due date:

How Are Due Dates Figured?

The doctor will estimate a due date by adding 40 weeks or 280 days to the first day of your last menstrual period. Remember, this is only an estimated date and only a small percentage of babies are actually born on the exact date.

I’ve Always Heard a Pregnancy Is 9 Months, Why do They Say 10 Months?

A pregnancy due date is actually calculated as 40 weeks from the first day of the last menstrual period. If you are counting “lunar months” which are only 28 days like a period cycle, then it is 10 “lunar months.” If you count full calendar months that are 30 to 31 days long, then it is really only 9 months. It will make counting the months easier if we count pregnancy month as lunar month, in which you are 10 months pregnancy when you reach the 40 weeks of pregnancy.

What If I Don’t Know When My Last Period Was Or If My Periods Are Irregular?

If your periods are normal then calculating the due date the traditional way should not be a problem. If your periods are irregular, or if you don’t remember the first day of your last period then you may have a little trouble determining how far along you are.

In this case, the doctor can do an ultrasound scan to measure the size of your baby. The technician will measure the baby from the “crown” or top of the head all the way down to the bottom or “rump.” The “crown/rump length” determination can be done anywhere from 10 to 13 weeks of pregnancy and is fairly accurate in determining the due date and the age of the pregnancy.

What About the Three Pregnancy Trimesters?

First let’s take a look at the trimesters of pregnancy: The months of pregnancy are grouped into 3 month segments known as trimesters. Your baby’s development and your body will experience changes during each period of 3 month trimesters. Here are how the trimesters and the symptoms you feel are broken down:

Pregnancy Trimesters

How You Will Feel

The First Trimester of Pregnancy (Week 1 through Week 12)

  • You will feel elated, nervous, excited or scared after finding out your pregnant. You may even cry more often.
  • You may be extra fatigued and need to sleep more.
  • You may have nausea and vomiting.

The Second Trimester of Pregnancy (Week 13 through Week 27)

  • Your fatigue will begin to subside and you will feel more energy.
  • Nausea and vomiting may disappear, but for some women it may last through pregnancy.
  • You will begin to put on weight and you will notice your baby bump growing.

The Third Trimester of Pregnancy (Week 28 through Week 40)

  • Your fatigue may come back due to the rapid growth of your baby.
  • You may have aches and pains do to baby’s size.

How Many Months Pregnant Am I?

Now you've got the answer to "How many weeks pregnant am I?" you may also wonder about how may months pregnant you are. The chart below will help you understand which month of pregnancy you are in. Keep in mind that the actual dates are only approximate. The first month of pregnancy begins one month after the first day of your last menstrual period. The table below outlines the months of pregnancy and how that corresponds to weeks:


What You May Be Feeling

Your Baby’s Progress

Helpful Tips For Good Health

Month 1

Weeks 0-3


During the first month, you may not have any pregnancy symptoms at all. Some people feel symptoms right away.

  • Implantation spotting. Not as much as a period.
  • Nausea and/or vomiting any time of day
  • Aversion to smells or certain foods
  • Tired feelings, needing naps
  • Needing to urinate more frequently
  • Crying or Anger spells
  • Breast soreness
  • Feeling faint
  • Food Cravings
  • Constipation

· The first week after conception your little baby will embed itself into the lining of your uterus. This is called “implantation.”

  • This month your baby will only be the size of a very small bean. The amniotic sac and umbilical cord will begin to form to protect and nourish your baby over the coming months.
  • Your baby’s nervous system and spinal cord begin to develop.
  • The heart forms and will begin beating soon.
  • Arm and leg buds begin to form.
  • Do not use alcohol. The first few weeks are a critical time for nervous system development and alcohol can cause serious damage known as “fetal alcohol syndrome.”
  • If you have a cat, do not change the cat litter. Cat feces contains toxoplasmosis that can cause birth defects.
  • Quit smoking.
  • You can try a pregnancy test during the first few weeks, but may not always be positive in urine until around the fifth week. Blood tests can detect pregnancy sooner.

Month 2

Weeks 4-7

  • Nausea and/or vomiting any time of day
  • Aversion to smells or certain foods
  • Tired feelings, needing naps
  • Needing to urinate more frequently
  • Crying or Anger spells
  • Breast soreness
  • Feeling faint
  • Food Cravings
  • Constipation
  • Headaches
  • The heart will begin to beat.
  • The end of the spinal column closes up.
  • Blood cells begin to develop.
  • The brain divides into five separate sections.
  • The eyes begin to form.
  • Your baby is about ¼ inch long now.
  • Get plenty of rest. Your baby is going through a very rapid period of development and this is tiring for newly pregnant moms!
  • Continue your exercise with doctor’s okay.
  • Eat a healthy and well balanced diet.
  • Use a bra with good support.
  • Call to schedule your first OB/GYN visit.

Month 3

Weeks 8-11

  • Nausea and/or vomiting any time of day
  • Aversion to smells or certain foods
  • Tired feelings, needing naps
  • Needing to urinate more frequently
  • Crying or Anger spells
  • Breast soreness
  • Feeling faint
  • Food Cravings
  • Constipation
  • During this month your embryo officially becomes a “fetus.”
  • The neck and muscles are now forming.
  • Your baby does move, but you may not feel it for a few more weeks or even months.
  • Hair follicles and nipples form.
  • Eyes and nose continue to form.
  • Your baby has finger and toenails now.
  • Tooth buds begin to form.
  • At the end of the month, your baby will be about 3 inches in length and weigh ½ ounce.
  • You may need to start wearing larger or looser clothing this month.
  • Continue to get plenty of rest and eat healthy.
  • Make sure you have your first appointment with the doctor that will be delivering your baby.

Month 4

Weeks 12-15


By this month, the above symptoms may begin to go away and you start to feel better. Some women, the above symptoms may continue throughout the entire pregnancy and this is also normal form some.

  • Slight flutters or “bubbles” when baby moves.
  • Waistline growth or “baby bump” appears.
  • Increased appetite and cravings.
  • Weight gain.
  • Discolored spots on skin.
  • Constipation
  • Baby becomes covered in a fine fuzz. This helps protect him or her from the environment.
  • Baby now has fingernails, eyebrows and eyelashes.
  • Ear buds are now forming into noticeable ears and can hear your voice.
  • Moving constantly.
  • Baby is now about 6 inches long and weighs about 5 ounces or less than one-half pound.
  • Continue to get plenty of rest, exercise and eat healthy.
  • You may need to switch to a good fitting maternity bra. Many of these are also designed for nursing after your baby is born.
  • Make an appointment for the AFP or “alpha-fetoprotein” blood test to check for birth defects. This should be done around 16 weeks.

Month 5

Weeks 16-19

  • You may begin to notice stretch marks from your expanding abdomen. These appear on your breasts, thighs, buttocks and lower abdomen.
  • Baby’s kicks will now feel more like a shove.
  • You may start to have increased discharge from the vagina.
  • Your breasts may begin leaking the first breast milk “colostrum.”
  • Hormones may cause gums to bleed.
  • Constipation
  • This is a huge growth period for baby.
  • His muscles are getting stronger.
  • He has teeth and possibly even hair on his head.
  • Your baby now sleeps and wakes up in cycles and you’re getting kicked a lot now.
  • The organs are forming and your baby is getting a nice layer of fat cells.
  • Baby is now about 7 inches long and weighs about 11 ounces.
  • Since you may be leaking some colostrum, you may need to buy some breast pads to insert in your bra. Colostrum can stain your clothing and show leakage onto your shirt.
  • Brush and floss your teeth well every day for bleeding gums.
  • Use a good lotion to help heal stretch marks after pregnancy.

Month 6

Weeks 20-23

  • Your “baby bump” is now very obvious.
  • You’re getting more blood and this may cause you to sweat and feel very warm.
  • You may feel pain in your pelvic bones as the weight of the baby begins to push down and your ribs get sore from baby pushing upward.
  • You may feel somewhat short of breath, especially after a big meal.
  • Constipation
  • Baby is really growing fast now.
  • Your baby’s skin looks reddish and wrinkly.
  • This is a period of rapid brain growth and the fatty sheaths that help the nerves transmit are beginning to form.
  • Baby is beginning to produce bowel movement known as “meconium.”
  • Baby is now about 14 inches long and weighs 1.6 pounds. Some babies can survive if born at around 24 weeks with intensive care.
  • Rest as needed with your feet elevated.
  • Dress in layers in case you begin to get too warm.
  • Try some “pelvic rock” exercises to help the pelvis stretch and relieve achiness with your doctor’s permission.
  • Eat smaller more frequent meals to prevent shortness of breath after eating.

Month 7

Weeks 24-27

  • Stretch marks may continue to enlarge as your belly grows.
  • You may start to feel some “practice” contractions known as Braxton-Hicks.
  • As baby pushes upward, you may get heartburn.
  • Low calcium levels may cause leg cramping.
  • Constipation
  • Your baby’s eyes can sense the light and dark and open and close regularly now.
  • He can hear sounds all around him now.
  • Fat cells are depositing to help him deal with temperature changes in the womb and after birth.
  • Your baby is now 16 inches long and weighs almost 3 pounds. If born at 28 weeks, there is a better chance for survival.
  • Continue to eat healthy, get rest and exercise as tolerated.
  • Contractions are usually infrequent and painless. If they continue or cause pain then you need to check with your doctor or birthing center.
  • Try not to eat 30 minutes prior to bedtime and prop your upper body up at night if heartburn is a problem during sleep.
  • Make sure you are getting adequate calcium in your diet with plenty of dairy, leafy greens and necessary supplements.

Month 8

Weeks 28-31

  • You’re starting to feel quite heavy and even a little off balance.
  • Your ribs and pelvis feel very sore at times from your growing baby.
  • You may be urinating a lot, especially during the night.
  • Worsening constipation
  • Increasing Shortness of breath
  • Increasing pressure in the pelvic area.
  • Your mostly developed baby is now just building up fat and gaining weight.
  • Baby turns head down and starts dropping into the birth canal.
  • Strong kicks and pushes.
  • Baby is about 18 inches long and weighs about 5 ½ pounds. Over 90% chance of survival if born now.
  • Take frequent rest breaks if you are on your feet a lot during the day. Keep your feet elevated.
  • Drink lots of fluids and eat a high fiber diet to help constipation and prevent the hemorrhoids common in pregnancy.
  • Try a “belly band” type belt to help relieve pelvic pressure.

Month 9

Weeks 32-35

  • Baby moves less due to decreased space.
  • Lower back pain.
  • Increasing Braxton-Hicks contractions.
  • Feelings of nervousness, excitement and fear.
  • Your baby is now fully developed and just gaining more weight. The lungs are the last to finish development.
  • You’re providing your baby with antibodies to illness and disease right now that will protect him or her the first few weeks of life.
  • Baby is about 18 to 20 inches long and weighs 6 to 9 pounds.
  • If you haven’t already, start your maternity leave from work to prepare for baby’s birth, get started.
  • Rest as much as possible over the coming weeks, you will need the strength.
  • Continue to eat healthy and get a little exercise. Walking is a great way to prepare the body for birth.
  • Call your doctor if baby moves less than 5 times an hour.
  • Go to the delivery department if contractions get stronger, more painful and closer together than usual, or if your water breaks.

Month 10

Weeks 36-40

  • You may be feeling very tired by now.
  • Increasing pressure on the pelvic floor.
  • Your appetite begins to decrease.
  • As baby drops into pelvis, breathing is easier.
  • Baby is ready to go any day now!
  • Call your doctor if baby moves less than 5 times an hour.
  • Go to the delivery department if contractions get stronger, more painful and closer together than usual, or if your water breaks.
  • Your doctor will probably see you every week this month until you deliver.