Is there a chance I'm pregnant?

My boyfriend and I were having unprotected sex and he came, not in me. then we were going for another round about 15 minutes later. I heard that if he pees after he cums, there won't be any semen in his system. But he didn't pee or anything. I sucked his dick to get the cum off. I didn't taste anything anymore when I was sucking and then we started having unprotected sex, again. Do you think I will be pregnant? Could his precum contain semen? HELP!