Would withdrawel bleeding during placebo week on birth control mean you're not pregnant?

Hello Meggyrshee,

Yes. During the fourth week of the menstrual cycle, women take birth control pills that do not contain active hormone.
This is the time when they experience bleeding. This monthly bleeding is not a “true” period. Instead, this is withdrawal bleeding. It is the the body’s reaction to not having the hormones it gets the other three weeks of the cycle.

Regards,
Maryann