Painful air in vagina

So my boyfriend and I had sex, I’ll describe it as missionary but with my ankles on his shoulders so he could go deep. Afterwards I got a pain in my lower abdomen. It hurt like cramps but I’m still a few weeks away from starting my next period. I assumed it’s from air being pushed so aggressively into me??? This has never happened before and it’s extremely uncomfortable. I’m laying down with a pillow under my butt and legs spread apart to try to help it escape. Its slowly easing up. For future reference, does anyone have any advice to either avoid it, or the best way to relieve the pain and get the air out. Or is it not air?