The first day of pregnancy is considered 14 days before ovulation. This is why, when your cycle is 28 days, your last menstrual date is considered your first day of pregnancy. This means that when we do IVF, if we do the pregnancy test 2 weeks after your egg collection and it is positive, you are 4 weeks pregnant already. We generally wait 2 or 3 more weeks to be able to see fetal heartbeat, so this is why on the day of the pregnancy viability scan you are already 6 or 7 weeks pregnant.