19 and a late period.

So I hooked up on Saturday the 23 of September. I don't usually do this type of thing not because there's anything wrong with it but because it's just not something I'm into. I didn't realize how close to my period I was. I'm on birth control and he didn't finish in me (sorry if that's tmi) but I'm now 2 days late for my period and starting to worry. I had a little bit of bleeding on this past Saturday but it was just spotting so I don't know if that was my period or if I should take a pregnancy test. Any advice?