Depo shot and pregnancy

So I was on the depo shot for 6 years. I decided last November to stop getting it. I read up on the subject and everything was telling me that it takes a year to fully get out of your system and even then it could take a while to get pregnant. My husband and I decided to not use condoms any more and if it happens it happens. I still haven't had a period. Its been a week and a half and I think I have symptoms but I'm not sure. I have taken a test and it came back negative but I think it was too early. So I'm confused as to if the symptoms are real or just in my head. Is it possible to get pregnant this early?