What day does everyone go off to know how far along they are, before going to the doctor? My last period was January 25th and I ovulated on the 7th of February and found out I was pregnant on the 19th. According to one app I'm 6w3d and due on Oct. 31st and according to glow I'm 6w1d due Nov. 2nd, however I thought it usually goes off from ovulation date or conception date in which I would be 4w3d.