How likely is it to get pregnant 8 days before period is due?

Pregnancy is known to have occured from sex on all and any days of the sex. If sex happened less than 72 hours ago, consider taking plan B. Visit this site for safe sex guidelines: : https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines If you do not wish to be pregnant, use contraception all the time, every time. You may consider implanted contraceptive, or IUD.