Irregular periods

Xela
Hi ladies, I'm 25 n for the past 3 years I've had very irregular periods. I think it's due to my weight gain. I'm 5'2" and 230 lbs. My periods used to last 5 days n I would get them every month. Now, I'll have about 6 periods a year or less. They vary quite randomly for example: I can have a week or 3 months between the next period n when I do get a period, it could sometimes 5 days or more than 2 weeks. It's driving me crazy! Is anyone else having this problem? Also, I don't plan to have kids and am still a virgin, but if I ever have a sexual relationship, do u think it's possible I might be sterile or do chances of me getting pregnant look good? Just wondering because something is definitely wrong down there lol! Thanks!