Condom falling off during sex

[jazzysteffy.livejournal.com]

I had sex about a week and a half ago and the condom came off inside me. It
didn't come out until the next day (about 12 hrs later) and I just pulled it out
and flushed it.

I could have been imagining it but I felt some soreness/pain in the area that
same day.

I'm on birth control, so I'm hoping I'm safe from getting pregnant - but can
having the condom stuck in you for that long cause any damage? Should I be
worried?

Thanks a lot guys.