I know what it is to worry about things like this, I am a neurotic first time mum with pnd - the worry has sent me round the twist,
I had / have some concerns about my ds although he's only 9 months, -anyway of course the medical profession will not take me seriously and fob me off with a wait and see line, - its frustrating and now they just write in notes that mum has pnd so I just look like a nutcase.
But basically the medical profession only treat things with medecines.
Developmental delays need something more. I'm not saying you should worry, I know nothing about this but you can only do something positive.
I thoroughly reccommend cranio - sacral oesteopathy, its brilliant and treats all manner of things and is especially beneficial for babies. My ds started crawling and cruising after a few sessions - of course thats not proof it could be co incidence and it won't work the same for everytbody, but its certainly worth doing and you will probably find that you are worrying about the worst case scenario but maybe its just a question of a small tension, or discomfort that needs addressing.
please think seriously about this because its a wonderful treatment and much more than any doctor will do.
(i'm not saying you are neurotic btw, just me but I don't want anyone else to go round the twist)
You need to crawl to show your baby and also when in tummy time put a cushion under their chest cos its very frustrating when they are lying down and can't lift up and the cushion gives the feeling of being elevated without it being exhausting for them