Tummy time Q

Just Me • Have a 4 year old daughter and a Newborn GLOW baby girl born 22/04/15..so in love 💕
When did/will you start tummy time? 
My little girl is 12 days old and the app I have said to start it now but I can't help but think she to young yet for it as we all know they can really whack there head down hard when learning to control it. With my first I never did tummy time and she was very advanced in meeting milestones eArly so is it really needed?