LMP November 4,2022
Sex with A November 12,2022 sperm went in
Sex with B November 20 pullout method
Ultra sound December 14,2022 5weeks , 6days which makes ovulation November 17.. which is the father ..
Well, Sunset, they are as accurate as they can be, and earlier ultrasounds are better for purposes of dating the start of the embryo than later ultrasounds. But, ultrasounds aren't primarily done to date the pregnancy but to make sure the baby is OK. Using them to try to split the difference between November 12 and November 20 is asking a lot.
The fact that it was a fifth-week ultrasound (almost 6 weeks) helps with the precision, since the embryo is big enough to see and measure by then, but will not have had time to possibly diverge from the usual growth rate for embryos. At that point the cells will have divided a certain amount and the development will be measurable, but later some babies grow faster and some grow a little slower, which is why there's a large margin for error by the 40th week. But in the 5th or 6th week, the margin for error is very small, like plus or minus 1 day.
I assume (because you didn't have the first guy pull out) that you prefer Mr. November 12 to be the dad. What you have going for you there is a couple of things. One is [given you ovulated on the 17th], Mr. November 12th's sperm can live that long, but your egg only lives 24-36 hours unless it is fertilized. Sperm that arrives on November 20 would be too late to catch an egg that came out on November 17. This suggests it was already fertilized by the time Mr. November 20 came along (unless of course the ultrasound is not as accurate as it seems it should be).
There is also that a theory called the Shettles method, though it isn't proven. The idea is that sperm carrying the male chromosome swim faster and die sooner, and sperm carrying the female chromosome live longer and swim slower. If the theory is correct (a big "if"), the baby being a girl points to the first guy.
Despite these two ideas, only if you were to get a prenatal DNA test would you know for totally sure at this point. Since you are obviously keeping the baby, I would suggest you opt to get the DNA test when the baby is born, because after the baby comes the tests are lots less expensive. If you can, test with both guys. But if it's not possible because the guy likeliest to be the dad doesn't know about the other guy, at least test with the guy likeliest to be the dad. This is done by cheek swabs, you and the baby and he should all do them right there at the lab at the hospital after the baby is born. If the guy you are testing doesn't know there was another guy, simply tell him that you need to do it for legal reasons, to have the guy's paternity right there in the baby's medical record. This would be a good idea for any woman not married to the dad of her baby, since the baby has rights to his or her father, and waiting to test until there is a hassle over child support or some other contentious issue can be a real problem. This is how to protect the baby from the very beginning, and if you tell him so, he'll probably do the test without wondering if you have another reason for wanting it done.