What do I need to do to get my period regular? I only have one once a year, if that.

You . You need to see your doctor for a work up of your amenorrhea (absent period). Lab tests including fsh, lh, tsh, and prolactin should be done to rule out a hormonal imbalance/issue. Depending on the results your doctor may start you on a birth control pill to regulate your cycle, or give you a hormone called Provera (medroxyprogesterone) for ten days or so to see if this stimulates bleeding. Your doctor will guide you through this process of uncovering why your cycles are absent. Best of luck.