Water or discharge?

How do you differentiate? I’m a first time mom and don’t want to go to the hospital if it’s not necessary with everything that’s going on.

I always wake up to quite a bit of discharge, but today was a bit more than usual. There was a wet spot about the size of a tennis ball (maybe a little less) on my underwear. I’m 37+3. Not feeling any sort of leaking throughout the day and didn’t fill up a panty liner. It’s the 2nd day in a row this happens. I don’t think it’s anything, but how do I know really?! 😩