What Causes Brownish Vaginal Discharge And Stomach Cramps?

I'm having light pink discharge when I wipe accompanied with clear discharge also. These past couple of days I've had really painful stomach cramps. I haven't taken a pregnancy test because I am not too concerned and think I am constipated. I don't poop normal, but I am worried about the slightly pinkish brownish discharge when I wipe after going pee. What is it a sign of?