Can this weird thing happening to my period be because im so stressed and scared?

Please help. Im really stressing and obsessing over this!!:( 'm 16 years old and I had unprotected sex on feb 10th or 11th (not sure) . My boobs got sore a week after , which NEVER has happend. Than Feb. 21 I got my period.. And my boobs stopped hurting. It was pretty normal period (heavy with clots) and i think it came around the right time because my sister always starts hers 2-3 days after me. and she started hers yesterday. Anyway yesterday FEB. 24 it has lightend and theres just tiny pink spotting. Im really scared. My period usually lasts about a week. Its now Feb.25 I just went to the rest room and i saw a little brown spotting on my pad and when i wiped a little faded pink came out. than i went to the restroom again and when i wiped and there was more pink/ bright red. im REALLY STRESSED OUT. & really really scared help? :( Also can this weird thing happening to me period be because im so stressed and scared?