Leaking amniotic fluid or normal discharge

I'm 30 weeks tomorrow and the past couple weeks my discharge has been insane! lots of it. but today I noticed when I went to the bathroom that my underware was really wet and it smelled differently then my normal discharge. I also notice when I go to sit or stand I get a small gush feeling but that's it. is it worth calling my doctor about or does this sound like normal pregnancy discharge in the 3rd trimester.