Grace asked:
I know they count the weeks of pregnancy by the date of the last period. So if the last period was on Dec. 1st for example, Jan 1st would be sometime around week 4.
But what about those with longer cycles? With cycles that are 50 days long for example. So if two women have their period on Dec. 1st, one with a regular cycle and the other with a longer cycle, I believe that they didn’t conceive on the same day.
Am I right? Please explain.
Yes, you are right. They go by the last date of your period at first. Eventually, an ultrasound will be done to confirm the fetal age and approximate date of conception. From there, you will be given your new due date.
Good luck and congrats!
It is counted exactly the same, however it’s more likely that the estimated due date might be off by a week or so if you have an irregular cycle. Your doctor will have a better idea after your ultrasounds.
Your right about the two not conceiving on the same day. But your due date is just an estimate. Your baby can safely come two weeks before to two weeks after. I believe you doctor will still calculate it the same because there is not enough difference to matter.
EDC is normally calculated by adding 7 days to the first day of the LMP(last period) then adding 9 months. The method only works with a 28 day cycle. Your physician will give you and estimate based on your LMP and adjust based on results of ultrasound.
It doesn’t matter how long your cycle is. You start counting from the first day of your last period. For instance, you last period started 12-1, say you ovulated 12-14, on 1-1 you would be 4 weeks pregnant. The goes for a woman with the same period start date with a ovualtion date on 12-20. When your doctor tells you your due date most use a 28-30 day cycle when giving you you due date. So if your last period was 12-1 you count backwards 7 days, giving you the 25th. Then count back 3 months, giving you September. Therefore your due date is Sept 25th. A due date is basically just a guesstimate. It gives a doctor a measuring point to base you exams off of. If you are measuring big or small your doctor can always move your due date back or forward. Only a small amount of babies are actually born on there due date.
I had probs with this coz my cycle is long too and no way of knowing when in the cycle I ovulated. Ultrasound is good to base the date on, but I prefer to just say im due in march and not pinpoint a date because I think its inaccurate. Drs will still go by the standard calculators for women with normal cycles and this drove me nuts with my midwife!