On the 28/04/13 I took a depo shot and I was suppose to take another one on the 23/06/13 but I didn't and on and on the 26 and 29 of June 2013 I had unprotected sex,so ever since I got the depo shot I've been spotting but it stopped 5days back but I having cramping and swollen breasts,headache and my tempreture is a bit high,so but I did blood pregnancy test it came negative on the 10th,so could I be pregnant or not?

You could be I was pregnant for almost 2 months on birth control and spotting before I realized I was pregnant

Any time you have sex, even if you're using protection, pregnancy is possible. The fact that you missed your shot makes it even more likely.

False negatives are very common. Wait for you next period, and if you miss it, test again.