Question: I’m pregnant and I’m not sure if my boyfriend or another man is the father of my baby. Around the time I was supposed to ovulate, my boyfriend ejaculated inside me. The next night I had sex with another guy, but I didn’t let him ejaculate inside me. Is it possible that the second guy got me pregnant with his pre-cum?
Assuming that you are correct about when you ovulated and that this 24 hour period is when you got you pregnant (rather than a few days before or after when you may have had sex with either of them), then your boyfriend would be the more likely father. This is because sperm are rarely in pre-ejaculate and, as a result, pre-ejaculate is rarely a substantial pregnancy risk.
Origin of Pre-Ejaculate
The fluids that make up pre-ejaculate mostly come from the Cowper’s glands which are two small pea-sized glands inside a man’s body toward the base of his penis. The fluids don’t have any sperm in them.
The only way that pre-ejaculate would end up having sperm in it is if there were leftover sperm hanging out in a man’s urethra and the pre-ejaculatory fluids, also called pre-cum, swept them up on their way outside the urethra.
If the guy you were cheating with had just ejaculated either from masturbation or partner sex, and then had sex with you, then there would be a greater chance that his pre-ejaculate may have picked up his leftover sperm. However, if he urinated between his last ejaculation and when he had sex with you, then his urine would have likely cleared any remaining sperm out of his urethra.
Who is the Father?
Because your boyfriend ejaculated inside of you and the second guy did not, there is a far greater chance that your boyfriend’s sperm fertilized your egg, resulting in a pregnancy. Again, this assumes that you know when you ovulated and became pregnant.
If you are wrong about when you ovulated, and if the guy you were cheating with came inside you on a different day, then it is still possible that he is the biological father of your baby. The only way to know for certain who is the biological father of your baby will be to have a paternity test conducted after your baby is born.