Pregnant and hungry v often???

RV, thx. i didnt know i was pregnant until mid 3rd month. i used to feel like fallin and head heavy and all when i was in 2nd month. i didnt know that time i was pregnant.
i m concerned now that i m enterin 4th mnth is it wrong to not eat for more than 8 hrs when i m sleepin... as i sleep more than 8 hrs i m worried if i m doin anythin wrong.
i m overweight so sub conciously i m a bit worried abt gainin too mch also. at the same time i dun wanna starve the baby so i eat whenever i m hungry. its only when i sleep that i dunno if i m doin anythin wrong for not eatin for so many hrs.