I was 16 weeks yesterday, so I know it's kinda early.
But you know the feeling you get if you smoke a ciggarette really quick, all light-headed and a bit dizzy and hot and fluttery, or if you have been bending down a lot and suddenly stand up and feel a bit faint?
Well I been getting feelings like that but low in my abdomen - make me knees go all funny too.
I have a lightheaded, dizzy belly (not lightheaded dizzy head

)
it only lasts for a moment, but its a very strange sensation