I am 3 weeks pregnant and noticed in the past day i have very light pink discharge when wiping after going for the first wee of the day and then this colour has changed to a dark brown / watery colour. There isn't a lot (no marks on my knickers) - just visual when i wipe after going to the loo. This is my first pregnancy so worrying that i may have lost the baby. I exercised yesterday and wondered if i have done something to the baby?