Anxiety of being Pregnant

The other night I had a fun time. But the thing is I’m getting anxious about being pregnant. I dont want to be. There was only precum and no actually ejaculation. But I don’t remember if he touched his pc then fing***ed me. He claims he didn’t use the same hand that touched his genitals. I got paranoid and got a plan B. My period is supposed start in 5-7 days. What should I do?