Condom inside of me

2 nights ago I lost my virginity to my boyfriend I’ve been dating for a couple of days. I’m only 14 and he’s only 13 so we aren’t as experienced. I made sure he used a condom but we only had XXL size and he has quite a small willy. He told me the condom fell off while we were having sex and I didn’t think much of it. Ever since I have been getting really bad stomach cramps and I still haven’t found the condom. I haven’t pooped it out yet so I have a feeling the condom is still inside of me. Do I tell my mum or see a doctor or ask him to help me?? Please help.

EDIT: I have a vaginal fistula which connects your vagina to another organ