What Causes Abdominal Pain And Spotting Before Menstruation?

Hi, may I answer your health queries right now ? Please type your query here...
I am 6 days before my next period. Been feeling pain in lower abdomen for last 3 wks, had some spotting about a week or so ago, I was starting to be suspicious of being pregnant, then today I had a cholesterol screen taken and all my numbers were "weird"per the tech, took a pregnancy test this afternoon, showed negative, what do you think?