Originally Posted by
CravenMorhead
You conceived after the 11th of March. You can't say that you ovulated on the 19th. That is a good guess, but it could have been before or after. Regardless your due often reflects the date of your last period not the conception
date, and even then it is scaled to the size of the fetus. It assumes that all fetuses grow at the same rate to the same size. So there is a bunch of wiggle room.
If he was Boinking her right before you got together then it could be his depending. It is odd that you got pregnant immediately, but ca sera.
The only way you're going to know if that kid is his is a DNA test afterwards. Farting around with conception dates and due dates is going to cause nothing but grief.