A.A.
Hey M.,
Don't want to be rude, but how old are you? Any chance you could be starting peri-menopause? Are you dieting or under stress? Menstrual cycles can always change especially if you aren't on birth control. I wouldn't panic just yet, but do take a pregnancy test just to rule that out. =)
Not that I am trying to push the topic, but perimenopause can start in the 30's...a couple years before real menopause hits and your body is not producing enough estrogen and causes irregular periods and other symptoms. Just a heads up...isn't being a woman grand sometimes =)