I have a baby boy who has just turned 9 months old. He has always hated tummy time and just cries whenever he is put on his tummy. He has no interest in crawling at all and is just happy to sit and play with his toys. We have tried several things to try and help encourage tummy time but nothing seems to be helping. He has been able to sit unaided since 6 and a half months old and is reaching his milestones but has not interest in crawling yet. Should I be worried? Should I contact the health visitor? Thank you!