My 3 month old has bad breath?!

So Saturday ago my 3 month old daughter had an appointment with her pediatrician and everything went good. She got some vaccinations and was prescribed multi vitamin with iron drops.

Later that day I start to notice a smell of pee and it was strong I thought maybe she had gotten some on our sheets while being changed. I would catch smells of it slightly throughout the day. only last night did I realize that it was coming from her mouth and it was strong (like old urine!) it is still continuous even after ive tried using a dampened clean baby rag to wash her mouth out after feedings, I would also like to add that she is breastfed so her bowl movements are usually a yellowish color which is normal. but today she went poop and it was a dark green color! what could this be? I am calling her pediatrician tomorrow but I still would like so know if anyone else has had this problem.