Is pregnancy calculated from the day of conception or implantation?

Pregnancy is calculated neither from the day of conception nor implantation. Instead, it is calculated starting from the first day of your last menstrual period. This makes it much easier for doctors and midwives to track the progress of your pregnancy. This day is known as gestational week 1, day 1, even though conception normally occurs around 2 weeks later, on day 14 of your cycle. For the first 2 weeks of pregnancy (gestational weeks 1 and 2), your egg travels down the fallopian tubes, is fertilized, and then implants into the lining of your womb (uterus).