I know this might sound stupid but I am extremely paranoid right now. Last month, I had sex, protected, but for a short period, the condom slipped and we made direct contact. My period did arrive three days later and seemed normal, but around 2 weeks ago, a started spotting a light pink color. With respect to the 28 day cycle, my period is now a week later. However, I have been experiencing sore breasts and slight cramps/back pains for a week and a half. Is is possible that I am pregnant even though I got my period last month? Or am I just overly paranoid and stressing?

It is possible, but it could also be the stress that is delaying your period. I assume that your periods are regular enough. The best course of action is to wait for another week so that you're two weeks late and then do a home pregnancy test with your first urine of the morning. That is the most concentrated urine and will be most likely to give a reading if there is anything there. The problem with the secondary symptoms, those other than the missed period, is that they can be indicative of a coming period.

Sperm can hang around for a while and if the right one is in the right place at the right time, it could impregnant you.