ok so, I started my antibiotics for my tooth about 5 days before I started my birth control (didn't…

ok so, I started my antibiotics for my tooth about 5 days before I started my birth control (didn't know it could have an effect on the BC). missed some pills eventually made them up, had some sex lol took test a week before I started my inactive green pills and it was negative. been very lightly bleeding for 3 days now, and I'm super gassy, that's normal right?