I’m so confused and nervous

Okay the last time I had sex was November 16th (I lost my virginity) I’ve had two cycles since. I’m supposed to come on my period now. So yesterday I had super light brownish red blood. I couldn’t even feel up a tampon and it’s completely stopped. I’m not pregnant I’ve gotten negative tests and everything. I just don’t know what to do or what’s happening. I’m scared and confused and I’m only 19.