Two

We're not going to be able to help you with no question.

If you had sex with two or more people in same time, there is no way to tell the birth father till the child is born, This is a common issue and we get many questions about this.Dates of conception is a educated guess, and give or take two weeks. So there is no way to know for sure. Until the child is born and a DNA test is done to determine the father

And why is this under Physics? If you wanted to post in the science area shouldn't it be under biology?