Extremely worried

So, my period has gone on for three days, today is the fourth day and it's going away. It's been extremely light, never soaked a pad, mixed with a lot of mucus.
I've been crampy, nauseous, with backache, and my boobs have been sore this whole time.
My boyfriend and I did have protected sex but he never ejaculated and we did it for five minutes (we used condoms and checked for holes after) 
I've been extremely stressed and worried after reading some of the posts that a light period means pregnancy, I've been crying and losing sleep and worrying my boyfriend. 
I don't know what could have caused this?😕
The only thing else we had done this month is I gave him a bj on my fertile days and I'm scared I may have touched Sperm and a little bit after went to the bathroom and touched myself 
I'm terrified and I don't know what's wrong with me. Any ideas?😔