Hi. I'm 28 years old, married.My regular period last for 5 to 6 days. My last regular period started Aug.7,2011. I expected my next period to come on the 4th of Sept. but it came on the 6th day and stopped after 3 days.This is the first time I experience this. I also felt something strange in my body few days ago, like frequent headaches, tenderness of breasts and frequent urination. Am I pregnant?