When is the right time to go to the hospital?

I dont want to be running to the hospital with every single pain, how do i know when is the right time? Im 30 weeks and my belly feels so sore at the bottom, usually when I wake up, sort of like period cramping. and sorry TMI but i have like a little clear fluid down there,not alot but i feel it on my underwear. I feel him moving most of the day, im just wondering whats normal