Mucus???

My son is 3 months and he eats the Similac Alimentum so it's hypoallergenic. I know mucus in poo is a sign of a milk allergy but he's already on that formula so that shouldn't be it. I've noticed today his poo is mucousy. He's gone twice and it's gross lol otherwise he's acting fine. He is kind of drooly and has a bit of a runny nose but nothing major. We all have runny noses lately. Should I be worried or has anyone dealt with it?? I KNOW what the Dr will say, so until it lasts a few days I'm not calling. They don't take me seriously unless it's urgent or it's been happening for a couple days. Just wondering if anyone has already dealt with it and can ease my mind.