Will accepting a clearing place make the other unis reject me?

Hi So yesterday I unfortunately didn't get the A level results I expected and was rejected from both my firm and insurance choices. I've since been offered 4 places for bioveterinary science through clearing. I'm not sure which university I'd like to go to out of those four. One of the universities needs an answer by tomorrow morning otherwise they'll take my provisional clearing place off me. If I accept that university tonight/early tomorrow morning and then decide I don't want to go there over the weekend, could I reject that university and add one of my other three? Or will doing that mean that my other three clearing places would be taken away from me?

Thanks in advance, and sorry for the long post! I hope it makes sense.