I've been on depo-provera my last shot nov. my cycle n dec. my cycle came again march light, but red having pregnant symptoms no cycle april&may could b the shot?

Unpredictable: The bleeding patterns with depoprovera are unpredictable. You are right that for some in takes the period away. For others it causes irregular bleeding. There is no "normal" for Depo-Provera users. The longer you are on it the higher the chance of no periods. The Mirena (levonorgestrel) iud may be a better option for you if you want to avoid pregnancy and stop having periods.