Period or miscarriage?

I am one of those that will start my period on the exact day I'm supposed to in the morning. I'm never late ever. I was a day and a half late and started bleeding very very heavy. The pain is horrible not like normal cramps would be. The pain is in my lower back, abdomen and pelvis. I'm bleeding through a pad every hour which is not normal either. I don't know if I'm having a period or a miscarriage since I am TTC. Should I go get checked out to be on the safe side or wait a few more days to see??