What happens if you swim in a dirty pool?

I went to my friends house yesterday and me and our other friend jumped in the pool fully clothed. It didn't have chlorine in it yet though and had a few bugs and leaves at the bottom. I didn't know that you could get sick. Our one friend actually went under the water so most likely got it in his mouth and stuff, but I didn't. I stayed above the water the whole time. It was only my neck and the rest of the bottom of my body in the water. All day today I kind of felt weird, like I was sweating and feel like I have a fever. When I check my temperature (in my mouth) it says I have 98.8 and 98.9, but I think it's broken because even when I don't have a temperature it still says I do. My friend who went under the water seems fine and isn't complaining about feeling sick so why do I? My parents say I look like I could have a fever and when they put their hand on my forehead they say they can't tell. I'm so terrified. Please help.