Late period by 2 weeks,haven't had sex since january.stopped th shot,periods every 15 days and now i missed it.took a preg test,negative.why no period?

Progesterone: From the information given, you stopped the depo shot. Progesterone takes up to 12 months to clear. As you recall, abnormal bleeding, bleeding every day or no bleeding at all or anything in between is entirely normal for progesterone only contraception. As the progesterone clears your system, your bleeding pattern will improve, however, until it clears abnormal bleeding will still occur.