My son is a smiley, giggling and happy little chap, which I am incredible grateful for, but I keep worrying he's not reaching developmental milestones with his friends. I tried tummy time from day one, but he hated it. I persisted but eventually he yelled as soon as he was being turned as he knew what was coming. At 6 months, his other friends were rolling back to front and front to back, and getting themselves quite mobile but my son only ever wanted to be on his back. After persisting for weeks, he figured out how to turn so the second he was on his front, he could get onto his back again straight away. And that is where he stays. He sits on his own and reaches for toys but if he overbalances and ends up laying on his front, he yells and gets into such a state. One mum told me to to leave him to it and let his frustration make him work out what to do but just how long should I stand by and watch my son crying histerically before I intervene? I don't do everything for him, I try to to encourage as much independence as possible, but at every step we seem to be getting left further and further behind. Now his friends are all crawling and their mums tell me I should be making the most of his being stationary, but he really really is the only one who isn't keeping up. I'm worried there are things I'm not doing, or things I'm doing wrong, which are hindering his development. I know all babies are different - I'm a teacher and constantly tell parents that all children are individuals and have their own strengths, but the worry about my own son won't leave me. I've stopped meeting the other mums as they always asked what new tricks he was up to, and I could only ever say that there were none. They talk about what their children do, and I can't contribute anything. I'm sorry this is so long but I'm worried and feel guilty that it's my fault, and that I'm a failure.