If you don't get your period for months and not pregnant. now periods come twice a month and heavy pain. what is this?

Hormonal imbalance: If you're having inconsistent periods, it could be a sign that you need a tune up. I would talk to your OB/GYN about your menstrual history. Is this something that's sudden and previously you had regular periods? Or is this something you've been struggling with for a long time? You might need to check your thyroid or try a few cycles of hormonal contraception.