TTC After one shot of Depo

So I was on the Depo shot the first time I got pregnant with my  daughter. It took me one year to get pregnant after I got off the shot. Now my fiancé and I are ttc our second child and in the past year I jumped from the Inpanon to the Patch and then to the Depo. I only took one shot of the Depo and I am worried it is going to take another year before I can get pregnant. Anyone of you ladies had any problems getting pregnant after birth control? Also I got my period twice in the month of February after I decided not to go back for my Depo and I have not gotten a period since. Should I be worried?