What Are The Chances Of Pregnancy After Using The Depo Shot?

i took a pregnancy test last night and a very faint line came up in the positive block then this mornings first urine i tested again and the same thing happen, a very faint line.

i decided to take another one this afternoon and it came out negative.

i did have my period and im currently spotting but i was on provera



can i be pregnant even though the test i did now says negative?