How do you know if what you are leaking is pee or amniotic fluid?

Loredana
So I've been wetting my underwear since yesterday not much but enough to notice it. How do I know if is pee or is amniotic fluid? I'm 27 weeks pregnant. I'm nervous. Don't know what to do. The wetting doesn't have colour. And I'm not so sure about the smell... my nose is bad right now.. can't smell almost anything.