Which Medication Will Help To Regularize Period?

I m 19 years old and I haven t taken my birth control everyday I m on lo loestrin and my periods are irregular. I wanna know what I can do to make my periods regular so I can know when I m fertile, I d like to have a baby. I do not wanna stay on birth control I ve heard prenatal vitamins help your hormones? But I don t think they re helping mine. I ve been told I may have endometriosis but no further testing was done I was also told I have dysfunctional uterine bleeding. Hope these diagnosis help. I also don t have insurance that gynecologists take unless you re pregnant. So I m in a bind.