ive missed my period for mre than just 2 months before and was never irregular you should go check with a doctor becsaue it just might be stress, or your period is changing and will be becoming irregular i didnt get my period due to the changes of my birth control but i reccomend you see a doctor
Well, how old are you? If over 45 then maybe it is menopause. If not and you were regular up until 6 month ago it may be an ovarian cist or something of the like. I had an ovarian cist and it caused my period to be late 2 weeks. If you have side pain that might be it.