Milk supply

So I've had a strong milk supply up until my baby was Two or two and a half months old then it slowly start decreasing and my period also came back. I talked to a nurse over the phone and she said it takes longer for a period to return while EBF. I've never supplemented and don't plan to unless emergencies come up. So far none have, but I'm wondering if these things are normal. First I was surprised my period came back so soon, I did heal extremely fast due to natural birth, but I'm confused if that's suppose to happen that soon with breastfeeding. Second, I'm concerned about my milk supply decreasing lately, I used to pump and have extra, but now I have nearly enough to meet my sons needs. I was curious about what was wrong and googled it. It just said milk can decrease if a women's period returns. What I'm looking for is answers to: If someone else has had this issue with their supply or knows if having your period this soon while EBF is normal?