Health Issue??

So, I am due for my period, but I haven't been experiencing any of my normal PMS symptoms (back pain, sore breasts, fatigue, bloating, and nausea) aside from moodiness. The other really weird thing is I've been having this brown vaginal discharge (so sorry, TMI), and it's globby and looks like it's old or dried blood. It doesn't smell any different from normal blood and there's no pain or discomfort. I'm really concerned because I'm only 23 so it can't be menopause, and I'm still a virgin, so it's not anything to do with pregnancy. I just want to know if anyone else has experienced this and if I should be worried? I've never experienced this before and it's honestly scaring me. I don't know if it was a weird period or if it's a new PMS symptom.