Will i bleed again in a week if i took plan b while i was on the last day of my period?

Maybe: Plan B can alter the menstrual 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.

You might: It would not be unexpected if you had some more bleeding in about a week. Just be sure to use foam and/or condoms till your cycle is regular again.