Pregnancy, Birth Control, Menstruation

Trying to get pregnant - stopped my BC last month after my pack was finished. Approx 2 and 1/2 weeks later I had lower uterine/ovary ache which was not very painful just annoying and lasted a couple days. My husband and I did have sex previous to that. I am now 2 days past my period due date and have been having mild cramps for 3 days with no period and had a negative pregnancy test yesterday. Could I be pregnant or just my body messed up after the pill? I did have completely normal, punctual cycles previous to taking BC.