) Once the doctor gives an estimated due date from an ultrasound, go home and either count backwards on a calendar
266 days, or else use an online conception calculator
. It will give you an estimated conception date.
Keep in mind a few things.
- Doctors begin the gestational-age count, or the "weeks pregnant," on the first day of the woman's last period, or on a calculated first day if she does not remember when it was or has irregular cycles.