Hi, Welcome and congratulation!! You aren't wrong. LOL Doctors due calculate from the time of menstruation which makes it seem like longer (10 months instead of 9). Pregnancy is 40 weeks with full term being considered at 38 weeks. It does kind of work out to be 10 months when you factor in that extra time of your last menstrual period. And first pregnancies often go over . . . I was 40 weeks plus 10 days! Well cooked baby! Overall though, actual conception is a best guess by all. So, are you asking how far along you really are? What was the date of your last menstrual period?