i had my period twice last month and it came once on december20th for 2 days then left is it just irreguler or that other thing?

Usually if you are pregnant, the bleeding stops. In some cases, the periods continue. It sounds more like you are having an irregular cycle. This could be brought on by stress, hormone changes, or an underlying medical condition. Most likely stress or hormones.

I would see how January pans out for you. If it's still crazy, you should go see the doctor to be sure nothing is wrong. He may put you on birth control to regulate your cycles.