An unplanned pregnancy can be very stressful. If you are pregnant or think you might be, you’re probably feeling many different emotions. Regardless of how you feel about being pregnant, one of the first questions you’ll probably ask is, “How can I calculate how many weeks pregnant I am?”
What is my LMP?
This term refers to the first day of your last menstrual period (LMP). It is the date used to calculate the gestation of a pregnancy. Your LMP is the start of your cycle. About 14 days after the first day of your period, an egg is released from one ovary. This is called ovulation.
The egg travels through the Fallopian tube over the next 12-14 hours. Conception happens when sperm fertilizes the egg. Sperm can live in the female reproductive tract for up to 5 days, so if a woman has unprotected sex several days before or during ovulation, she could become pregnant.
In a 28-day cycle, your period would be due 14 days after ovulation or 28 days from your LMP. There are lots of reasons a period could be late. If you do not get your period when you expect it, and you’ve been sexually active, you can take a home pregnancy test. You can also contact Jewel Women’s Center to schedule a free pregnancy test with our medical team.
What if you don’t know your LMP?
Not everyone keeps track of their menstrual cycle which can make it difficult to know your LMP. Additionally, some women do not follow a 28-day cycle. This leaves room for confusion when attempting to calculate how many weeks pregnant a person is.
Ultrasound is the most accurate tool for calculating how many weeks pregnant a person is, especially during the first trimester. It uses measurements to determine gestational age. When someone has a positive pregnancy test at Jewel, they are offered a free ultrasound to further confirm viability and answer the question, “How many weeks pregnant am I?”
An example
Let’s look at an example. If a woman starts her period on January 1 and has a 28-day cycle, she will ovulate approximately January 14. About 14 days later – on January 28 – she would be due for her period. If she conceives during her cycle, she will be 4 weeks pregnant on the day she misses her period. If she goes for an ultrasound on February 12 – two weeks after missing her period – her ultrasound measurements will most likely be calculated as 6 weeks pregnant.
Ultrasound is the best way to calculate how many weeks pregnant
During early pregnancy, the best way to calculate how many weeks pregnant you are is to have an ultrasound. Jewel Women’s Center offers pregnancy testing and ultrasound as part of our pregnancy consultation. This appointment is designed to answer several questions:
- Are you truly pregnant? Is the pregnancy viable and likely to continue? Does it have a heartbeat?
- Is the pregnancy growing in the right place in your body?
- How many weeks old is the pregnancy?
Contact Jewel today to schedule a free pregnancy consultation.
