Question for doctors/nurses/medical school students or professional rowers?!!?

I've been rowing for only about a year now, but have never capsized before in my life. River water grosses me out.. So, anyway, today I was coxing a quad (a boat of four rowers and one cox). The rowers were practising some blade exersises in the river today and we somehow ended up capsizing at night, in the dark. Me, being the cox, was trapped underwater for a minute and, in my panic, I'm certain I swallowed a gulp of river water. I'm okay now, I've drank 2 cans of coke (apparently coke kills the bacteria), but i'm worried about any water diseases I could have recieved? I've heared of some diseases which can kill you, and now I'm freaking out a little bit. Could anyone enlighten me on some river water diseases, how serious they are and perhaps give me some advice? Thanks!