I've never experienced this problem in the past, but after sex with my boyfriend, minutes later my stomache bloats and it can last for up to a couple of hours. I've had sti tests at my local gp and they all came back clear. We don't use condoms, I'm on the contraceptive pill. My stomache doesn't hurt afterwards, just feels full. I'm just a little concerned and am worried this could mean we'd have difficulties trying to get pregnant in the future. Sorry to sound crude, but the bloating isn't just when my boyfriend ejaculates inside me through sex, I have also bloated after oral sex a few times.