Would taking three plan b pills in a month affect my menstrual cycle?

Definitely: Plan B is a progestin and taking it even once in a given cycle will effect your menstrual cycle.It is to be used only in emergencies and not as a regular means of contraception.If u have had to use it 3 times in one cycle you are having way too many emergencies. Remember it is only 95% effective if taken within 24 hours after intercourse. You need to start a more reliable method B4 u get pregnant.

Good chance.: Emergency contraception can induce menstrual flow changes (spotting, bleeding, early or late period). When taken x 3, that increases chances of menstrual changes. If you are taking Plan B this often - then you need to consistently use a regular form of birth control.