Technically, pregnancy is counted from the first day of your last period, when actually, you probably didn’t get pregnant until about two weeks later. It is weird, but unless you know your exact conception date, the closest you’re going to get is the first day of your last period. So, to tell how far along you are exactly, count the days from the day you got your period last, until today, and you’ll know how far along you are, to a doctor at least.
I hope I helped, Good Luck,
Michelle J.