Please Help. (Girls only Please)?

Im 21 and I have had irregular periods for years but one time i didn't have one for 14 months and that was a year and a half ago. Right now Ive been off of mine for 3-4 months. Im a virgin and not taking any medication. I'm worried. I don't have the money to go to a doctor because im unemployed. and I don't have insurance... I've read that girls can go in to an early menopause, and I don't want that to happen. Have any of you had this problem?