To calculate baby weeks, count from the first day of your Last Menstrual Period (LMP), adding 280 days (40 weeks) or using the "Naegele's rule" (add 7 days to LMP, subtract 3 months, add 1 year), as this is the standard method healthcare providers use, though an early ultrasound offers the most accurate age. If you know your conception date, add 266 days (38 weeks).
Last Menstrual Period (LMP)
It calculates your due date by counting 40 weeks (280 days) from the first day of your last menstrual period. This method assumes a regular 28-day cycle and ovulation occurring around day 14 of your cycle.
Yes, it seems like you're "4 weeks pregnant" when you're actually only 2 weeks past conception because pregnancy is dated from the first day of your last period, not when the egg is fertilized (which happens around week 2). So, if you feel like you just conceived, you're likely at the medical "4-week" mark, meaning your body is preparing for ovulation or just ovulating, and you'll get a positive test soon if pregnant, with conception happening around week 3 or 4.
In the 5th week of pregnancy, your baby is actually three weeks old and has finally been "drawn into" the uterus. Read on to discover when it is worth taking a pregnancy test, why your little one now looks like a little UFO and other things that still need to happen at the start of the first trimester.
To calculate pregnancy weeks, use the first day of your last menstrual period (LMP) as day one, then count 40 weeks (280 days) from that date for your due date, or calculate the days between your LMP and today to find your current gestational age; a simpler method is to subtract three months from your LMP date and add seven days, which gives you the due date. Pregnancy weeks track from your last period, not conception, so you're technically "pregnant" for about two weeks before ovulation.
For example, if today's date is 14/07/2024 and the last period was 07/04/2024, the process is as follows: Gestational age = (14-07) (07-04) * 4 ⅓ Gestational age = (7) days and (3 months) * 4 ⅓ Gestational age = 7 days and 13 weeks, which means 14 weeks or 4 months.
At 30 weeks pregnant, you are in your seventh month, marking the beginning or middle of the third trimester, with the eighth month typically starting around week 31 or 32, as pregnancy months don't align perfectly with weeks but generally cover 4-5 weeks each.
So when doctors say a woman is six weeks pregnant, it typically means the embryo started developing about four weeks ago.
The "worst week" of pregnancy varies, but many women find the first trimester, particularly weeks 8-10, to be the most challenging due to intense morning sickness (nausea/vomiting peaking with hormone surges), extreme fatigue, and heightened emotional changes, though some experience severe symptoms like hyperemesis gravidarum (HG) requiring medical attention, while others face discomforts in later pregnancy.
Between 5 ½ to 6 ½ weeks, a fetal pole or even a fetal heartbeat may be detected by vaginal ultrasound.
This is because pregnancy is counted from the first day of the woman's last period, not the date of conception, which generally occurs 2 weeks later. Pregnancy is roughly divided into 3 stages known as trimesters of about 3 months each : first trimester – conception to 12 weeks. second trimester – 13 to 27 weeks.
Don't eat raw meat, deli meat, raw seafood, or raw eggs. Avoid soft cheese and unpasteurized dairy, like Brie and blue cheese. And don't eat fish that contains a lot of mercury, like shark and swordfish. Don't touch kitty litter or cat poop.
In the second trimester, ultrasounds are less accurate, and the due date is only adjusted if the difference is greater than 2 weeks. In the third trimester, ultrasounds are the least accurate for estimating the due date, with an error margin of up to 3 weeks.
Ultrasound. The best way to determine your conception date is with a pregnancy confirmation ultrasound. Early pregnancy ultrasounds can determine the age of your growing baby and when you likely conceived.
For example, a fertilised egg may have implanted in your womb just 2 weeks ago, but if the first day of your last period was 4 weeks ago, this means you're officially 4 weeks pregnant. Pregnancy normally lasts between 37 weeks to 42 weeks from the first day of your last period.
A month is more than 4 weeks, averaging about 4.3 weeks (4 weeks and 2 or 3 days), because months have 30 or 31 days (except February, with 28/29), not exactly 28 days (4 weeks). So, while 4 weeks is a common estimate, it's not precise; 3 weeks (21 days) is too short, but some consider 4 weeks a useful shorthand, especially for things like pregnancy.
Your risk of miscarriage is greatest between weeks 0 and 10. In the early days of pregnancy, you likely don't yet know you're pregnant. A miscarriage may simply seem like a late period. Most women don't realize they're pregnant until at least four weeks of pregnancy.
If there are problems with your pregnancy or your baby's health, you may need to have your baby early. But if you have a choice and you're planning to schedule your baby's birth, it's recommended to wait until at least 39 weeks.
You should start to feel your baby move between 16 to 24 weeks of pregnancy. If this is your first baby, you might not feel movements until after 20 weeks.
There's no perfect time to share your pregnancy—do what feels right for you. Many wait until after the first trimester. Miscarriage risk drops after 13 weeks, but it's also OK to tell trusted loved ones earlier for support.
At 6 weeks gestation, the embryo has a steady heartbeat around 110 beats per minute! Only 22 days after conception or 5 weeks and 1 day gestation, the embryo's heart starts beating. This heartbeat will not stop until the individual dies.
A pregnancy is divided into trimesters: the first trimester is from week 1 to the end of week 12. the second trimester is from week 13 to the end of week 26. the third trimester is from week 27 to the end of the pregnancy.
Pregnancy is supposed to be about 40 weeks but most babies haven't mastered timekeeping yet. It's best to pack your bags around the 30-week mark, just to be safe. The last thing you want is to go into labour when you're queueing for last-minute supplies. Oh and no, three bags isn't too much.
For example, women who have chronic health problems, such as high blood pressure or diabetes, who become pregnant may be considered to have high-risk pregnancies—even if the condition is well controlled. Other factors, such as infections, injuries, and disorders of pregnancy, can also put a pregnancy at high risk.