Possible miscarriage?

Need some help deciphering my situation. I'm on the pill. I started the sugar pills the Sunday prior to last. I didn't get my period. I started getting some cramping on Monday into Tuesday. On Wednesday i lightly spotted. Took a pregnancy test and it was negative. Thursday and Friday I felt fine. On Saturday I became sick with a migraine episode. I haven't had a migraine in over 2 years. But when I do i have nausea and dizziness. Sunday I still had the migraine, nausea and dizziness. Sunday night, I started a new pill pack. That night and it Monday early morning, I woke up in a panic with bad cramping. I went to the bathroom and was bleeding. I thought it was my period so I put on a maxi pad and went back to bed after taking some more migraine meds. Monday morning I woke up with blood everywhere and bled through my bedsheets. I bled pretty heavy all of Monday into Tuesday. Today my bleeding is a lot lighter but still passing some clots. I'm very fatigued and still kinda dizzy. Doctor won't see me until Friday. Would it be possible that I had a miscarriage?