i am a 45 year old female. I am a mother of 3, ages, 19, 20, 24. I had my tubes tied after my youngest. I realized last month i didn't have a period. I experienced all of the premenstrual symptoms. The symptoms have not stopped, still no period,. The cramps are now in my lower abdomen, back, as if i'm in labor; i'm also experiencing sharp pains, headache, light headiness. I am very uncomfortable. This morning, after intercourse, i had a somewhat bloody discharge, but nothing more, I took a home pregnancy test on Friday, but the results were negative. What could this be? please help