Cervical cancer?

Earlier this year around January, I started to notice I was having watery blood discharge. I’m January I tested positive for a really bad yeast infection and got it treated, then had another one shortly after. It wasn’t until today that I looked and saw I had a thick, black discharge. I have the hormonal IUD and don’t usually get regular periods although with the cramping I believe I have my period. Is this normal? Should I be concerned? I was told that since I am only 20 it is very unlikely that it could be cervical cancer so they won’t test me but I have never had a period that heavy and thick