Could i possibly be pregnant?

Alicia

Hi i was on the depo shot for a little over a uear and have been off of it for about 5months . ive had irregular periods the whole time i was on the shot and my last period was on the 5th of may and ended on the 18th of may. I havent had a period since

, ive noticed my breast are swollen and tender, and my emotions have been crazy. I also took a pregnancy test a week ago but it was negative but am not sure if i took it to early. Can anybody help me out?