how do you know its amniotic fluid ?

[enigma]

( sorry if TMI )

For the past few days ive had increased discharge , but it has a watery consistency .. at its worst in the morning when I wake up or when I sit down , I read that during the end of the pregnancy discharge increases , but today I had a thought - what if im leaking amniotic fluid !? .. is there something that makes amniotic fluid stand out from normal discharge? I read from google that amniotic fluid will " run down your leg " .. this isnt that much or that bad so im confused.. My next appointment at the hospital is on Monday morning , should I wait till then ( since this has been going on for a few days already ).. or should I call them ( which I seem to be doing a lot of lately ) ??
Any suggestions , much appreciated