Natural family planning

Joker
I see a lot of you ladies are trying to conceive but I'm on the other end trying not to conceive I have 3 babies under 3 and we just cannot do another one right now I however cannot take any form of hormone birth control nor do I want anything implanted into me im trying to go the natural route any tips for a first-time tracker on what day is to not have sex and does this app help any