Dark Period Blood???

I’m 18 years old and a Virgin (so I cant be pregnant). I got my period late today, which is normal for me since it’s usually off schedule anyways. However, my period blood is darker than usual and the flow is slower. I had gotten cramps a few days earlier, so I was a bit surprised that I didn’t get my period then. But I got it today and all the conditions that darker blood (brownish with a red tint) matches with us pregnancy and menopause. Any ideas what’s going on?