Brown/Black clumped discharge?

Hi, I’m a teen and I’m starting to get a bit worried because for the past week, when I go to the bathroom I notice there is usually what I would describe as a small ball of a dark brown/black colour and when I wipe there is brown coloured discharge.

If this is anything, I haven’t had my period but it’s irregular anyways so I don’t know if it has an influence on this and I would have gotten my period around this week if it came.

I was thinking that maybe there was a blockage because my hymen is quite intact and I have noticed that it is impossible for me to insert a tampon into my vagina, but also I don’t think this would make sense seeing as I have had periods before and they’ve all been normal, (irregular) but when they come normal.