DS is nearly 10 months and has a lopsided crawl on his stomach where he uses his right hand and leg and his left forearm (not hand and wrist) to pull himself. He drags his left leg. He's been doing this for some time and I thought he would progress to 'normal' crawling but hasn't. He does,sometimes, get onto his hands and knees but only rocks and then when goes to crawl gets back into the stomach lopsided thing. He doesn't show any interest in pulling himself up. He can stand well and hold onto the sofa or holds onto my hands (he can't stand alone). He uses his left hand and kicks with his left leg though does show a preference to the right. Am I worrying over nothing? I read somewhere that babies shouldn't show a left/right handed preference until 12-18 months. I know it's silly but at these mum groups I see other kids pulling up at his age and he's still on his belly doing this weird crawl. Thanks