I am sure you are fine - my OB with DS2 told me it depends on where the placenta is - kind o flike hitting someone through a phonebook (!!) - so it is cushioned and harder to feel. i found it reassuring to see on the screen him kicking around but not feel it - made me realise it was just 'cushioned'. however, i do think it is better to be safe so if you are really worried and it seems less than you are used to (with this preg) - try all the usual things like cold drinks etc and if no mvts then go get it chcked. i would prefer to feel silly than to be worried or for there to be an issue.
I am sure it is fine though. xxx