in december, my tubes will have been tied for 6 years. in the past couple of weeks, i have been feeling different. i have headaches, indigestion, back cramps, front cramps, feeling extremely hingry after eating and feeling tired when i dont normally. my last period was shorter than normal and i only bled heavily on the first day overnight. i have taken pregnancy tests but they come up negative. i have like a week and a half til my next peeiod, but could i be pregnant?