From shot to pill

Okay so last month I got off the depo shot, and switched to the pill. I finished the whole month and still haven't had a period (I was on the depo for almost 4 years and didn't have periods during that time). The doctor said I might not have a period for a while because of the shot but I'm still getting nervous? Maybe I'm paranoid, but I was wondering if any other girls went from shot to pill, and if so how long did it take for you to start getting regular periods?