antibiotics, the pill, and UTI

So I've been taking antibiotics for 5 days because my sister had a staph infection so we were all being safe, so I stopped taking my BC during those 5 days and would just start back up again when it was done because my mom told me it would cancel out the BC, but two days ago I developed a UTI, but it has nothing to do with the staph infection or the antibiotics, just a coinsidence, but I started taking pills for it two days ago and today I woke up with super heavy bleeding but no pain from my vagina and I'm not sure what to do or what happened but I started taking my BC again.