Possibly Infected

I had unprotected sex with someone I thought I can trust but apparently I was wrong. My friend told me that one of his old sex partners had multiple partners while with him. I suddenly get a call from him about some girl claiming she got something from him. He told me he was clean but should I still get tested to be sure? I’m so scared because this is the first time that I’ve done something like this!!! PLEASE HELP!!