How likely is it that I contracted HIV from receiving oral?

I'm a man, and I received oral sex from someone whose status I do not know, though I have heard that he is clean. I did not use protection. It lasted for about a minute, and I did not ejaculate. I poured mouthwash on my genitals afterwards to make sure I had no cuts and I didn't feel a sting. Is it likely I have HIV and should I get tested?