Had mirena (levonorgestrel) taken out in january. bled all of january. havent had a period since... should i be worried?

Many options: The IUD is out so now you are back whatever your body would do naturalIy. Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. If there is a concern for pregnancy then do a home pregnancy test. There are many options available to help regulate the menstrual cycle.