CM in 17th week of pregnancy with mild cramping!

I woke up this morning for the first time and noticed I had soaked through my underwear with clear discharge. Being a first time pregnant woman - I immediately began to think the worst because I also had some light cramping that felt like menstrul cramps. 
I went to the ER, and they did an amniotic fluid test to settle my mind and said it was negative. 
Any ladies experience increased watery clear discharge at this time? Or should I go see my OB?