Leaking fluid or just discharge? 38w6d

K • Mommy to Ava and Kieran 💕
I was sitting on my bed, and when I moved I saw a wet spot about the size of a quarter..didn't feel anything like, leaking or gushing but my underwear was moist so I went and checked and there was some white discharge. I've had that throughout pregnancy but never had it leave a wet mark where I was sitting. I have a dr appointment tomorrow morning..do you think this is just discharge and ok to wait for my appointment?