I'm driving myself crazy! On around the 22nd September hubby and I had sex, we didn't use any protection because we have used the withdrawal method for years now and it's done us right so far. Anyways, for a week now I have had period type cramping, not as bad, but constant. Two days ago I felt a very sharp twinge for a second or two, and the cramps continued. I have since noticed a very watery brown discharge on two occasions. Could this be implantation? Or just the start of my period. I never keep track.