Transition to Milk

First time mama here. We spoke with our daughter pediatrician who gave the go ahead to start and transition her to whole milk. We began this Saturday. Poor baby is also breaking 3-4 teeth at once so she is very drooly and has some minor congestion. My hubby and I noticed a few red bumps on the back of her neck. We stopped the milk (in case it is a reaction to that) but they’re still present. My husband thinks it might be from drool at night or just heat rash. I guess I’m just nervous it’s from the milk. We have an appointment with her doctor in a week for her actual 12 months so I’ll definitely bring it up then. I guess I’m just being overly worried lol and needed to “vent” 😂