I had sex with my SO last night and this morning when I woke up (TMI) and got out of bed I release ALOT of fluid. I went to the bathroom to check and my underwear were very wet and more fluid started running down my leg. My question is could this be fertile watery CM ? Or is it just left over semen from 12 hours prior ? Or both ?

I'm just not sure how long seminal fluid stays in before it all comes out. Usually, for me it "dries up" pretty well by the next morning and I haven't had this "gush" of fluid before. I am also within my fertile window.