Me and my girlfriend have been having lots of sex since she got pregnant she is now 3 months and we had sex a few hours ago I released in her 1 time and after she went to the restroom and her vagina lips were swollen could you possibly tell me what's going on? This is also the 1st time this has happened

The vaginal lips SHOULD swell during intercourse. It goes down after a little while. It's totally normal.