OK I'm a little confused on how long my cycle is. Nov and Dec my period came around the 21st and Jan on the 17th. So should I just average those. I was thinking 30 day cycle sounded right. I am on day 31 and no period.

The January one may have been just a bit off. Give it another week or so and see if your period shows up. If not, try a test at that time.

You could buy a dollar store test... They work really well... They should be able to pick up if you are pregnant by now... Don't spend too much money on a test when you still have time for your period to tell you that you are not pregnant.