I got my first depo provera shot about 13ish days ago and my boyfriend and I had unprotected sex in a spa in the weekend twice. Is there any chance I could be pregnant? My doctor said that the injection was safe enough to use by itself but I don't know and he said it takes 3 weeks for the injection to start working? Does it?! I googled it and on local family planning websites it says that the injection starts working in 7 days. But another one said it starts working in 5 days if you have your period? And another said it works immediately? One said it takes a month to work? Please tell me the correct answer! Is there any chance I could be pregnant? Please! I'm really freaking out I can't get pregnant; I'm too young! Also; does anybody have any experiences with the depo shot that they'd like to share? Ah omg thank you in advance! I'm totally freaking out now. I've already had one pregnancy scare before and it was awful so when does the shot start working? Is there any chance I could be pregnant? Also; if its of any relevance my period was due in a few days; on the day I got the shot. So I haven't had my period and the shot has completely stopped my periods.