not crawling or mobile at all!

My little man will be 11 months on the 31st of July, and he's not even crawling!! He's attempting to get on all fours but he just can't seem to do it, he doesn't pull to stand on furniture either (he has got strong legs and likes to stand when I stand him up) he literally isnt mobile, should I be worried, they are seeing him again at 12 months, picture because he's gorgeous 💙💙