I started lo loestrin on the first day of my period which was 6-7 days ago. condom broke so i took plan b 6 hr after. chances of getting pregnant?

Very little chance: Plan B can alter the menstrual bleeding for the cycle in which Plan B was taken, and sometimes the next cycle too, so there may be some irregular spotting. The birth control pills should be continued. 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.