Ok So I Lost My Virginity 6 Days Ago And

Ok so i lost my virginity 6 days ago and at first i was super sore and felt nauseous and felt like i would throw up so i got scared but he swears up and down he wore protection and everything.. but i remover him saying it fell off but he says he had one on and didn’t cum inside me but I’m starting to feel sick here and there and getting cramps and lower back pains... WHAT DO I DO