Abnormal period sos

Ive been on my period for 10 days now, its normal flow but it keeps stopping for a few hours and then starting again normal flow? Im still having cramps too I have a doctors appointment tomorrow but wanted an idea of what's wrong as I'm really worried now? advice? Any past experience that ended okay or not okay? if you had a bad outcome please don't hold back I just need to know what might be happening :( I wasn't pregnant and I'm not coming of BC or on it!