Period question

Lissette
I have a super irregular period (I'm talking like going years without one) but when I do have my period I get really bad pains and when I go to wipe I notice blood clots (or what I think to be clots; black and sticky globs). I'm 24 and not trying to conceive, I just want to know what others have experienced so that I can be more informed and prepared to go to my doctor.