Water break or just night sweat?

J

I'm 39 weeks now but ive been having night sweats a lot most nights, tonight is one of the heavy ones where ive changed pajamas 3 times now.. i was really sweaty again. How am i supposed to know of its sweat or water break at this point at night ? If i sit up with new underwear on will it leak at a point more? No point in smelling when i can only smell sweat on all the clothing :(