Yet another cheating post!

My husband is cheating on me. I didn't initially mean to find out, but he left his phone at home while running to the store. There was a few texts and I didn't know who "Ami" was. I left it alone because girls are just people to and people can't get through life talking to only one sex! Ami proceeds to text through dinner and then I get yelled at because my phone goes off 5 times because of work that "shouldn't be that important". It was only because I looked at mine and he left his for later. 2 days later he was in the shower and an Indian girl (not Ami) had messaged him and asked about seeing him again. I spent the day debating about going through his phone and a few days later he left it laying around again. I figured out the lock after a few tries and sure enough there are texts about how she left her panties in his car. What a sad movie move to play! So how long so I have to confront him about it? I have a tonne of work to get done by December 1st and we just had a baby 3 months ago. He cheated when it was convenient for him, so I don't want to bring it up and move until it's convenient for me. I Am not worried about a lawyer or anything to do with the divorce at this point. everything is pretty much separate already as this is my second marriage and I was prepared for the cheating.