So my question is I had my last period 2/10 & when I calculated the due date it says 11/17 but when I got my ultrasound it said 11/14. But unpleasantly I had two sexual partners at my time of conception... The first it was like everyday between 2/20-now. With no protection but he says he pulled out each time. The second guy was on 2/22 & 2/23 But we definitely used protection both times & I'm almost positive it didn't break. So by that which guy is more than likely the father? Im almost certain it's the first but he still has doubts & it worries me.

Due to the closeness of the encounters it will be virtually impossible to calculate before the birt, only a DNA test would be able to positively establish paternity.

My days if ovulation according to my period was also 2/24 but according to my 11 week u/s it was 2/21... If that helps

Gestational dating is Best Guess based on available evidence and is my no means an exact science.

But it SEEMS more like it would be by the first, right?

Honestly, it could have been Santa.
You need a DNA test to prove who it actually was.
It is IMPOSSIBLE to work out who it was from the dates given as they are far too close to call either way.

One more question. Is it possible to get pregnant like 3-4 days before your lmp because when I add up my weeks it doesn't make sense to any of those dates. It always calculates back to the week before I had my last period..?

One more question. Is it possible to get pregnant like 3-4 days before your lmp because when I add up my weeks it doesn't make sense to any of those dates. It always calculates back to the week before I had my last period..?

Yes, it is possible to get pregnant then. And as they are tying to say, your charts are worthless about ovulation, those are estimates and are not exact, many women ovulate at totally different times, unless you were testing ovulation you have no idea.

Next the date of conception is an estimate, even at the doctor, if they have you a date, it is give or take one or even two week.

So there is no way to even guess at who the father is.

A condom has a 3 to 18 percent failure rate, and often the failure will not be seen.

Pull out is not effective either.

There is no way to know the father at this time.

You will have to wait till the child is born and have a DNA test done