KrowdFit does not receive any female health data from the Fitbit API. We only see the activity health counters and their related data. In fact Fitbit does not share female health data with anyone at this time. From the Fitbit knowledge base below:

"Can I share my period data?

You can choose to use your female health data to help facilitate conversations with your doctor, providing a clearer picture of your menstrual cycle for more personalized care. At this time, you can’t directly share your female health tracking data from the Fitbit app with anyone, including your partner. 

Fitbit invests heavily in security measures to protect consumer privacy and keep data safe. We use a combination of technical, administrative, and physical controls to maintain the security of user data."

[SOURCE] https://help.fitbit.com/articles/en_US/Help_article/2333#share