3 months PP and 3 days late

I have had two consecutive periods. I am now three days late for my period. My boyfriend and I use the pull out method (stupid IK) but I do not like the way birthcontrol makes me gain weight and puts me in horrible crying moods. I bought a pregnancy test which was negative but my last pregnancy I didn’t get a positive till I was a week late. I really do not want to be pregnant but I will love whatever I am given. Has anyone else gotten pregnant shortly after having a baby? If so when did you test and did it work out?