Girl question?? Please help xxxxxxx?

Ok I'm not sexually active or anyhing and recently I have lost 7kg in 2 months so I have lost my period and border line of being underweight. Sometimes I get these sharp pains inside my vagina like a life is dabbing but it only last for a couple of seconds and keeps persisting for about 2 mins. Then I get like these air pops out of my vag. Is it because my period has gone out of whack?