So if you conceive and have sex the day you conceive can that person be the father?

[Cashdoll30]

I had a ultrasound and it’s saying I conceived on the 17th of February I didn’t know I was pregnant but ended up having sex that night the person pulled out but is it possible that that person could be the dad

[AnnieBrooke]

A person who pulled out could be the dad, yes. But the assumption that you conceived on February 17 might be mistaken. It's pretty hard to get that pinpoint of accuracy when using an ultrasound to try to determine what day you conceived. How far along in the pregnancy was the ultrasound?

[AnnieBrooke]

Also, when was the sex with the guy who pulled out, and when was sex with anyone else around the same time?

[Cashdoll30]

I had a period February 3-7 I had sex with guy A. February 9th until the 15th without pulling out I then had sex with guy B on the 17th nomore then 5 seconds without protection also but we didn’t go all the way I got up then he ejaculated mins later on his on I then began to have sex with guy A. From the 19th until the 25th without pulling out I found out I was 4 weeks pregnant threw blood work on March 3rd I then had a follow up appointment with a ultrasound from the obg and was given November 10th as my due date

[AnnieBrooke]

And when was the ultrasound? You say it was a follow-up appointment, was it the same week as the blood test on March 3?

[Cashdoll30]

The following week I was 5 weeks by then

[AnnieBrooke]

Given the additional information you've listed, it sounds like the guy with whom you had unprotected sex February 9-15 and 19-25 has the strongest chance of being the father.
The brief penetration on the 17th before the guy pulled out could have produced the child, but it is not as likely.

This is because the first guy released lots of sperm in your body the week before ovulation (and sperm lasts 4-6 days in your reproductive tract). The second guy would only have had sperm in his pre-ejaculatory fluid on the 17th if he had ejaculated recently before the sex with you (such as from a wet dream, masturbation or sex). The first guy had the most chances, and the odds would favor him even more if the second guy knew for sure that he had not had an ejaculation for several days before having sex with you. (Unfortunately, you can't rely on a guy's report for this information. Wet dreams can happen and the guy not wake up. Or, they might not want to fess up to having masturbated or had sex with someone else.)

If this is not enough for your peace of mind, you can get a prenatal DNA test at Ravgen or the DDC with both men. Doing a DNA test before the baby comes is much more costly than one done after the baby is born, but at least you would know now instead of later.

If you intend to keep the baby no matter who is the father, just tell both men that there is a very, very slim chance the guy from the 17th is the dad, and though it's only a slim chance, they should both do a DNA test with you and the baby when the baby is born. Test with both guys at the hospital when the baby comes, and never wonder again.