Could this be early menopause?!?

Okay so lately I've been really mean and crabby or irritable,gained a bit of weight and gassy...my stomach has been a lil hard I'm assuming from the gas...I have pcos and I feel odd stuff goin on in or around my uterus such as a fluttering sensation on the left side amongst other oddities...is this something to be worried about? Also I've had quite a few hot flashes. Ill be 21 soon.