Amniotic Fluid

Im 20 weeks and I woke up in the middle of the night to pee and then walked into my kitchen to get some water. On the way back to my bedroom a small amount of fluid came out into my underwear. It soaked about a quarter to half dollar size spot in my underwear and was clear and watery. Then it stopped and I wiped it up and went back to bed. Is that normal leakage after laying down for a while or does that sounds like a small amniotic fluid leak?