Brown-Dark Brown Spotting

My period has never been regular, sometimes I'll get it two months in a row and then I won't get it for 3 months afterwards. But this time it's kind of different. I haven't had a period since July and right now I'm experiencing extremely dark and gooey discharge that looks NOTHING like the blood I usually have on my period. I have no clue what's going on since it's never happened before, not on birth control, I'm a virgin, etc. and the flow of discharge is only a little bit every couple of hours, I don't need a panty liner but it still stains my underwear due to the color. Anyone else have this happen? I'm so confused and idk what to do.