hi hokonepooh,
the purpose of tummy time is to strengthen the baby's neck and back bone. it will help his sitting and crawling skill as well. so if you baby still not lift his head up, then do more often.
put some of his favorite toys in front of him when he is on his tummy to get his attention. it will help b'cos my baby was doing the same.
Thanks. I think you're right. So far, I only put him on his tummy for no more than 5 times.. because I am afraid he is going to vomit after the exercise..
I'll take your advice. By the way, his favourite toy is his daddy