My husband had a vasectomy 6mnths ago. Just recently i had to go to the emergency room b/c i was having severe abdominal pain. They did some blood work including a blood pregnancy test and the pregnancy test came back positive, i was shocked. The next day i went to the local heath department and had a urine pregnancy test done and it came back negative, i also bought one at the store and it was also negative. I have a history of hemergic ovarian cysts, and i have heard that it may throw off the results of a pregnancy test. Is it possible that the blood test was wrong?