I usually get my period around the 16 -18 of every month. I was recently sexually active & during the intercourse the condom that was used broke. I started to see after about 2 weeks after that my breast started to get tender & I had a few stomach pains, nausea, and cramps. Today I purchased a pregnancy test, but it was one from the dollar store like a really really really cheap brand and I took it before i suspected the 1st missed day of my period. Because of the cheapness in the brand could my test have come out inaccurate or may it be because i took it before the first day of my missed period?