Hello. 13 days ago my boyfriend and I were dry humping. He had boxers on, I was with my panties for the most part. He didn't ejaculate. I thought I would have my period 4-5 days after this, on February 1st, but I didn't - exactly on that day (or maybe on February 2nd), 5 days after dry humping, I got brown discharge and dark-brown spotting. This lasted for about two days with light cramps (it was mostly just brown discharge like before period). From that day and even now my breasts are sore, on this Monday I got really bad cramps along with the need to pee more often (which sometimes happens before my period), I got so paranoid that I even bought an early pregnancy test and it was negative (after 7 days when I got brown discharge and spotting). Can my period be late just because I had a stressful month because of my exams? I know it's not possible to get pregnant like that but I'm just so paranoid because I know about implantation bleeding. I'm scared because I've never had dark-brown spotting before and my period (if it can be called a period) has never been so short before.
Thank you for your help.