Had sex. Unprotected. He did not ejaculate inside of me. Took plan b within 24 hours. Chances of pregnancy? Also does plan b have side effects?

Pregnancy unlikely. Plan B (or other emergency contraceptive pills) can alter the menstrual bleeding for the cycle in which Plan B was taken, and sometimes the next cycle too. One should be sure to check a home pregnancy test about 3 weeks after sex, because Plan B works most of the time, but not all the time.