please need answers

Good afternoon, on November 2 2017 I started spotting all the way to November 28. I haven't been on any birth control. september 6 I was due for the depo but never went to get it. A week after I was due for the depo I had a regular period.now fast forward to December 28 I haven't gotten my period and my breasts feel very sore and heavy for the past 4 weeks straight and I've been feeling nauseas and my back been hurting but today i got a pregnancy test from the dollar store (blue dye) and got a negative can I still be pregnant?