How can I tell who is the father of my unborn baby?

[sarita58]

I took my first ultrasound when I was7 weeks and 5 days. Doing the math, the embryo was fertilized Feb 3rd.I slept with my ex 2 days before thaton Feb 1st.  and Feb 2nd and 3rd with my fiance. My fiance and I got in a really big fight, I was drunk he was drunk and told me to get lost. The thing is my fiance and I made up and had make up sex the day before and after, everytime unprotected. With my ex it was unprotected but only once and drunk.
At this point I am worried and scared. My ex is black and my fiance is Hispanic, so once the baby is born, the truth will come out. Im 4months now and my fiance has stopped drinking, working hard, he is so happy and excited. I am too with this in the back of mind.

[AnnieBrooke]

In what way did you "do the math"? Did you count back the 7 weeks 5 days on a calendar? Did you take the due date given to you at that seventh-week ultrasound and put it in an online calculator? or what?

[AnnieBrooke]

Was that first ultrasound on March 29?