Hi GeoMamma,
This is my first post, so apologies if I miss any appropriate etiquette
Our dd 4 (nearly 5) is in a similar place, and at first I worried about it, but now I am inclined to believe she is working on other things as has been suggested above, because in other ways her maturity levels have sky rocketed. But if anything seems like 'learning' she's just not interested at the moment. Hoping her curiosity comes back though! (and actually she's been doing a bit of the Brain Pop website and reciting bits of info to me just off the cuff, so she's obviously keen on learning something - but maybe just isn't keen on my style at the moment). Not so useful as advice I know, but maybe comforting to know he's not the only one?
We just have dd and she is in preschool a couple of mornings a week - I can't imagine having to cope with 2 and first trimester pregnancy, whilst also having to respond to dd's intensity! Hope you have a chance to look after yourself too
Take care!