1 Week Pregnant: What are the Symptoms of Pregnancy?

Taking the time machine back to Week 1 of pregnancy? Or curious to know when exactly pregnancy starts? What is the genesis of pregnancy like? Let’s find out what happens in Week 1 of pregnancy.

Week 1 starts on the first day of your menstrual period

calendar period menstrual cycle

When counting the weeks of pregnancy, a week is 7 days, a month is set at 28 days, and the expected delivery date is fixed at exactly 40 weeks. An average pregnancy lasts from 265 to 295 days (280±15 days) and is based on the assumption that the first day of the menstrual period is Day 0 of the pregnancy.

This first day of your last menstrual period (LNP) is the day from which gestational age is calculated. The gestational age of pregnancy is different from the “real” gestational age of the fetus – commonly referred to as “fetal age” and which starts from Week 3 of pregnancy, when the egg is fertilized. However, expecting moms will usually be given the age of their babies in terms of gestational age (the start of pregnancy from the first day of the LMP).

1 week pregnant: Pregnancy from a bird’s eye view

woman notebook

Pregnancy is divided into 3 trimesters as follows:

Trimester 1: Week 1 Day 0 – Week 13 Day 6
Trimester 2: Week 14 Day 0 – Week 27 Day 6
Trimester 3: Week 28 Day 0 – Week 40 Day 6

The end of the 40 weeks of pregnancy is your Estimated Delivery Date (EDD). However, even though pregnancy weeks include the 2 weeks in which your baby is not yet formed, your baby will be referred to by practitioners as __ weeks in terms of gestational age (from Day 0 of pregnancy). Confusing? Just remember that it all starts from Day 0 of your LMP!

The start of pregnancy: Follicular phase

female reproductive system

When your menstrual cycle begins, the follicular phase also starts. Follicles are spheres containing fluid located in your ovaries, and they will produce the egg that eventually becomes your baby. The start of your menstrual cycle means that the pituitary gland in the brain releases the pituitary hormone, which in turn leads to the secretion of the follicle-stimulating hormone (FSH). The FSH causes the follicles to produce estradiol, and together, they work to further develop the egg follicle.

The follicular phase can be as long as about two weeks, and the last 5 days of this phase is termed the ovulation phase. The matured egg will be released at the end of the ovulation phase which is sometime in Week 2 of pregnancy.

Though there is no baby in you in Week 1 of pregnancy and you’re having your menstrual period, your body is gearing for that possibility this week. It’ll take some time, but at the end of Week 2, you’ll be waiting with your mature egg for a miracle to happen!

1 week pregnant: Be ready for pregnancy


When you are 1 Week pregnant, a pregnancy test will not yield any results because there is no egg produced yet! It’s the start of your period, but also the official start of your pregnancy.

However, it is important that you take care of your own body so that you’re physically prepared to have a baby. Pay a little more attention to everyday things like having a healthy diet, have as stress-free a lifestyle as possible and ensure that your body is not exposed to the cold. Small efforts will go a long way in creating the healthiest womb environment you can offer to your (future) baby!