Firstly, ms can be unpredictable - if you are coming to the end of it, you might go up and down like a yo-yo. BUT, don't discount that you might have a bug - so if it continues, and you can't keep iceblocks down then get some medical advice.

Secondly, little bubba will take what he/she needs, and if that means you are left with nothing - that's what will be done. (I am lactose-intolerant, and couldn't consume enough calcium for my bubs - so they took if from my bones - therefore I always broke bones when pregnant)

Good luck!