Is there a problem or is it my BC?

I recently ran out of BC while on my period so I hurried and made an appointment to get new ones. The appointment was in the next two days and during those two days I got off my period. Then, I started taking my BC again. So I only missed two days of taking it. I have had migraines every day since I started taking it again. And then yesterday I started spotting. Now, I am basically on my period and I am really heavy. I've missed taking my BC before but this never ever happened. Is this normal?