Weird cycles...anyone else?

I was on the depo shot until last year (off it for 13 months now) and when I came off it, I didn't get my period back til May. May and June were very light, July, August and September were normal. October was a bit heavy. Then in November I was 4 days late (I used to have a 28 day schedule). I reset my period tracker and just figured it was stress. Then in December I was 6 days late, so again I reset my tracker, but I also lengthened the number of cycle days to 34. Today would be day one of af but she's a no show again (so far). I don't want to get my hopes up thinking I might be pregnant, so if you have experienced something like this or have ideas/thoughts/advice, I'm all ears.