Amniotic fluid or discharge?

I've had a watery thin, yellowish- tan discharge for about 24 hours... That have soaked up two whole panty liners. I've noticed a few gushes between last night and today, along with tons of cramping contractions. I'm due on Friday and was wondering if anyone else has had this happen? I've been to L&D three times this month thinking my water was leaking but all three tests came up negative.