TMI: always wet, watery discharge?

Na
I wear panty liners every day.
From about weeks 26+ (I'm 30 now) I've been having incredibly watery (basically water) discharge and my liner is always at least a little brown after several hours. It smells like it's just pee, when I pee and wipe it's always normal and my baby is doing fine. 
I'm just reading online now and people say it may be amniotic fluid? Wouldn't it have run out by now if that were true, it's been happening so long and I haven't felt anything strange at all! Please opinions. It's late now but I'm calling my nurse hotline in the daytime tomorrow about it.