![The Billings Ovulation Method®](https://d2j6dbq0eux0bg.cloudfront.net/images/4761406/619731652.jpg)
How to Use the Billings Ovulation Method® - the 4 Rules
A handy DL size card which details the Rules of the Billings Ovulation Method® to achieve or avoid pregnancy. An explanation is given for the reason for each of the Rules.
Perfect for your handbag, bedside table, book mark etc