Bleeding on Active Pills

I have been on the combo pill for the second time since September or October. No issues with period in placebo week; normal as it was before pregnancy. This month, I started spotting 3 days ago and yesterday evening it was bleeding like a normal period for me. I’m still on active pills; my placebo is next week. Normally on placebo I don’t have a period until the very end of the week about to start new package. No changes in dosage have been made and no new medicines other than a daily multivitamin that I just started on Sunday. Today, I have been extremely miserable with aches, cramps, and severe bloating(at least 3 lbs; I know because losing weight intentionally currently so monitoring my weight. What could be the cause of this?