Could I be pregnant again?

Before I got pregnant with my daughter I had very irregular periods. I went on the pill in December but my insurance stopped covering my birth control (beyaz) so I stopped at the beginning of April (which is also when I had my last period). I had what I thought was bleeding from stopping the birth control when I should have had my period (breakthrough bleeding, I believe is the term?) in May. I haven't had any symptoms or anything besides some cramping two days ago but not again since then. I took a pregnancy test a week ago and it was negative. But could I still be pregnant?