Long period for 13 days

Periods were irregular up until December. Now January,my period has been heavy for 13 days straight.

Spoke to my doctor but weren’t helpful and just said it’s hormones with no questions asked or tests done.

Doctor advised to go on the pill but I’m TTC.

Does anybody think what it could be as my period has been very long and trying to track when I can ovulate.

Thank you xx