My one month old has been on her tummy a couple of times on her play mate. I did so because she is starting to get pretty strong with her neck while burping. My friend, whose son is 9 days younger pretty much told me I was a horrible person for doing this because she felt my LO was too young. I asked my pedi when to introduce and he said when I felt comfortable doing so. We have only done it twice in the past week and other than burping on the shoulder she has never been on her tummy on the play mat before this week. Am I wrong? When did you first introduce tummy time with your LO?