Rolling over??

Tiffany • William Dalas born September 18,2016.💙👶🏼 Teen Mom. 💕 YouTube: Dalas’ Mommy
At what age did your baby roll over from tummy to back? My son turned a month old yesterday and a couple of days ago he rolled over for the first time. Now every time we put him on his stomach for tummy time he rolls over so we have to roll him over every time. Is this normal?