Ive been having weird periods since July, (week late period, early period, than last 3 periods were brown, and only are when I wipe). I haven't had to wear tampons for the last 3 periods. I've asked a nurse and she told me to take pregnancy tests, and they all came back negative. (it sparked that I could be pregnant because I've been also gaining weight). Again, the pee tests were negative. What's going on with me? Especially with the brown periods?