Hey,first of all how old are u?sometimes it depends on how old you are. If u are in your early teens its possible that u ovulate really late resulting in a long liteal phase hence af comes late like after maybe 35 days
Well if you have abstained for a year i advise you speak to your health care provider to try and find out why it is like that..you may find its nothing.good luck...
Missing your period can indicate a lot. Stress and dehydration can be some of the causes. Sometimes when you're very distressed or you havent been drink enough water, your period can come later/earlier than usual. If your period doesn't come within a few weeks from the day that you were you supposed to have it, try checking in with your doctor.