Sex on day 26 of 30 day cycle, took plan b within 17 hours, what is the chance of pregnancy?

Not pregnant: The only way you could be pregnant is if you ovulated a week later than your usual cycle and the Plan B was not effective. The chances of a pregnancy occurring in this situation if you have regular 30 day cycles is probably rare or not possible. Ovulating late can occur during high periods of stress or significant health changes to the body. If this isn't the case, you are probably not pregnant.

Slim: If your cycles are normally 30 days you would normally ovulate around day 15-16 or your cycle. The opportunity for fertilization after ovulation is probably less than 48 hours so day 26 you would be most likely safe.