Why do i show a negative pregnancy test, even though my period is 4 months late?

Can be other issues.: First, after 4 months, you probably should be aware if you're pregnant. You likely had symptoms of nausea, vomiting, and a redness on your face known as the mask of pregnancy. If you are certain you're pregnant, you might have done the test wrong or it was weak positive. If you're not sure of pregnancy, you might have an issue like polycystic ovarian disease. See your dr. And find out for sure.