"i have been on depo for almost two years and it works like a charm! i never go past the 5 day period to get the shot and it is crucial for it to work to not exceed the time of your next shot. when i first started i did bleed for a month but it was not heavy. my periods lasted 8 days and cramps were horrible before the shot so it wasn&#039;t that big of a deal for me. now i don&#039;t get periods ever and ever so often i might spot for a day or two. to be completely frank my partner and i do not use protection and i have not gotten pregnant so as far as contraceptives go this one is wonderful! i did experience dryness at first but it has since gone away."