I Was Having Sex With My Partner And The Condom

I was having sex with my partner and the condom slipped off at the end but we're not sure whether any semen made it inside me because it was also on the bed. I took the morning after pill less than 24 hours later. 7 hours after I took the pill, I went to the bathroom and it hurt to urinate. is this a side effect? what does this mean? does this mean it didn't work? could I be pregnant?