When will my periods come back?

I got put on the depo shot on October 11, 2012. Got the shots until September 3, 2013 which was when I got the implant in my arm. I had my implant removed due to health reasons July 30, 2014. I didn't have a period or spotting at all until September 15, 2014. Didn't have a period in October. November and December were normal and on time. When January came I didn't get a period, didn't get one for February either. Any idea when they'll straighten out and what can I do to help speed up the process?