Water breaking?

Today I am 39 weeks. At last weeks appt I was 2-3 cm dilated and 80% effaced. This morning I woke up to use the bathroom and my underwear was wet with a clear thin liquid. I changed my underwear and went back to sleep. About an hour later I got up again to use the bathroom and there was more clear liquid in my underwear but not significant enough o have to change my underwear. I can’t tell if this is discharge like I’ve been getting for a while now or if my water is slowly leaking.