Mm.. is there a reason you’re asking? As in.. you don’t want baby to do tummy time? For my first baby, we didn’t start tummy time till very late, so all her gross motor milestones were delayed, eg. Crawling, standing, etc. She couldn’t even prop herself up properly till after 5 months. So I wouldn’t recommend not doing tummy time. My second baby started early, and had good head control since she was 6 weeks old. She can already roll from her front to back at 3.5 months old.