Scarleteen

Hello,
a few weeks ago i had a colposcopy and a biopsy was required.
ever since the procedure whenever me and my boyfriend have sex (both protected and unprotected) i have been getting lower abdomen pain for a while after we are done, i am on birth control and take the pill at the same time every day so i dont think it is due to being pregnant, but could it be something serious?
im quite worried about it

That's not unusual: often after colposcopies with cervical biopsies, doctors advise patients to wait one to three weeks (sometimes less, sometimes more) before having intercourse because of both the risk of infection, but also because pain or tenderness with it -- sometimes involving the whole pelvic region, not just the vagina -- to some degree is likely.

I'd suggest you call the healthcare provider who ordered these procedures for you and let them know. They'll be able to determine by talking with you if this is a situation where they want to follow up and make sure everything is okay or not, and can advise you about this soundly.