Milk coming in?

Hey ladies, question!?

So My son is 15 months old and we haven’t breastfed in about 10-11 months due to him constantly being sick and not gaining adequate weight I had to stop and switch to formula, but these last few days my boobs have been huge, tingly, sore, and I’ve started having come out of them. I had my period last month about 2 weeks ago and have sex in the mean time. But I’m kinda freaking out! Like major freaking out! My boobs got huge and sore right before I found out I was pregnant with my son