Thanks for writing to us with your health concern.
The symptoms that you describe are not specific for pregnancy
Also, they are not typical side effects of plan B
The bleeding 6 days after taking it was the withdrawal bleeding, which is commonly experienced by most women.
Cramps and stomach aches also would persist for a few days.
The plan B can delay or prepone your normal periods by a week, or maybe, upto 10 days.
There was no ejaculation so you are mostly safe.
However, take a pregnancy test 3 weeks after the encounter happened, in case you do not have your normal period by then.