What's the probability of a girl getting pregnant 5 days after her period and taking the plan b one step pill 22 hours after sex.

Should be low: The Plan B within 22 hours of intercourse is 90% effective. When you say 5 days after period, do you mean after the start or end of period. If 5 days after start, unlikely you were near ovulation. If 5 days after end of period, and length is 5-7 days, then you could have been getting pretty close to ovulation again, increasing the risk. Encourage you to see doc regarding ongoing birth control!