Does Having Depo Shot Lead To Delay In Periods?

I had a tubal implant put in back in Dec. and just had the X-ray to confirm my tubes were blocked in March. I haven t had a period since I had the procedure done. My doctor told me it s because the depo shot I had back in Nov. hasn t wore off yet. They gave me a pregnancy test in March but it was Negative.Now I m starting to worry I m emotional,tired all the time and I m starting to shed really bad. Is this normal or is it just all in head?