Looking at what you've put I'd be inclined to think Asperges, but at two it's probably too early to tell. There's some definite signs though.
As for the hv saying there's nowt wrong, this is what happened when my older son (now age almost four) was being assessed.
Stage One: I notice that although he can recite nursery rhymes and stories at under 2.5, he can't tell us things, ask for things or chat to us. He appears to have very limited understanding and engages in repeptitive behaviour. A hv comes round, listens to me talk and declares him to be normal.
Stage Two: It's a few months later and my second son has been born. Other hvs at the clinic start asking guarded questions about my older son, does he do this, can he do that? I am torn between thinking I'm over neurotic and seeing a lad who does not behave like any other 2.5 year old I know.
Stage Three. I decide to stop worrying and get on with things. I go to the hvs' clinic to ask them to cancel a home visit and to tell me if I'm being neurotic. HV says "no", that they have concerns themselves, that they have spoken to a GP (these are different hvs from the first one) and that the GP agrees and wants me to make an appointment for Ds1.
Stage Four: Appointment made by GP for Ds1 to be seen by a paeditrician, who subsequently says he appears to be on the spectrum and refers him for a multidisciplinary assessment.
Stage Five: Multidisciplinary assessment concludes, at the age of two years nine months, that there is little doubt he is on the spectrum, that his communication deficits and understanding is severe and that he needs to attend a special nursery.
Stage Six: Ds1 will be four in just under two weeks. He still cannot ask for what he wants other than pulling you over to the item, he has very limited understanding. He has no awareness of his toilet needs and can't tell you when he's been or when he needs to go, or reply if you ask him. He cannot undress himself properly and can only dress himself with simple stuff. He can tell you numbers, colours, shapes, letters, but struggles to understand a simple choice of "would you like juice or milk?" We are having to have a meeting next week to decide what school he goes to and at the moment it doesn't look like mainstream is an option. As it is he hopefully has the option of continuing on to the wonderful special school his nursery is attached to.
At just over two his differences seemed mild, but a lack of progress in many areas and his skills and difficulties becoming more uneven means that now more and more people other than professionals are noticing he is not like a typically developing child.