please help!!

a week before my period my cramps were bad. and then in the same week i got irritation from fabric softener dryer sheets, thought it could have been a yeast infection so i started taking miconazole 7.

this was a week before my period. then my period came. but i was still using the medicine. when id use it i wouldn’t bleed much. i got done doing the miconazole and then i started bleeding and hurting very VERY heavily. i was wearing a tampon and pad and still bleeding through. i put a supper tampon in and not even a hour later it bleed through. my left side and stomach and back been in severe pain. i thought i could be pregnant having a miscarriage so i took a test and it was automatically negative.

i started my period august 12th and it’s now august 22nd!!!

someone PLEASE give me any information on what could be happening.