No period since December 9th

So...here's my story. Went off birth control in March, got married in September and started trying in October. My periods have been horribly irregular. Last time I went from October 12th to December 9th with no period so went and got a blood test. Negative of course. We really tried hard this month but all I have gotten are negative UPT. Am I even ovulating?? Should I go to the doctor and see what's up or why I have such irregular periods?