Missed period

I did not have a cycle this month. I'm a lil concerned because I'm very regular with my periods every month. Up until recently when things started changing. Last month I was 10 days late and now this month I didn't get one at all. I'm not sexually active so I can't be pregnant. I figured I would wait it out through March to see if I get a cycle but if not, I'm speaking to my doctor about it. Does anyone now what this could possibly mean?