Suggest Treatment For Irregular Periods

Hi I'm an 18 yr old Female I started getting my period in 7th grade and got it monthly for a yr steadily and heavily but after 7th grade came and went I started skipping my period and now at 18 yrs of age i've possibly only gotten my period twice this year... I'm not sure what i should do i mean i tired to wait it out eat healthy and exercise but nothings worked a friend suggested i go on the pill but my parents where against it now that i'm 18 i'm wondering what should i do?