Rules of the Billings Method

Early Day Rules (rules for the
pre-ovulatory phase)

• Rule 1 – avoid intercourse on
  days of heavy bleeding during menstruation.
  [Ovulation might occur quite early in the cycle and menstrual
  bleeding could obscure mucus.]

• Rule 2 – Alternate evenings are
  available for intercourse when these days have been recognized
  as infertile. (Basic Infertile Pattern  (BIP) )
  [Evenings are recommended for intercourse during the BIP
  as the woman needs to be in an upright position for a few hours
  for cervical mucus to make its presence felt at the vulva. Seminal
  fluid on the day following intercourse could obscure the mucus.
  It is important to allow time for the seminal fluid to disappear
  and to confirm the BIP is still present by avoiding intercourse
  on consecutive evenings. ]

• Rule 3 – Avoid intercourse on
  any day of discharge or bleeding which interrupts the Basic
  Infertile Pattern. Allow 3 days of the Basic Infertile Pattern
  afterwards before intercourse is resumed on the fourth evening.
  Rule 2 continues.
  [Waiting will enable the woman to either recognise the Peak
  in which case the Peak Rule is used; or, when the change is
  an interruption of the BIP caused by raised oestrogens, the
  hormonal level will return to a basic low level and the woman
  will recognise a return of the BIP. She counts 3 days to enable
  the hormones to stabilise before resuming intercourse applying
  Early Day Rule 2.]

The Peak Rule (Rule 4):

• From the beginning of the fourth
  day following the Peak until the end of the cycle, intercourse
  is available every day at any time.
  [Ovulation occurs on the Peak Day or days 1 or 2 following
  the Peak. The egg will live for 12-24 hours
  unless fertilised. The third day after the Peak is to allow
  for the life time of the egg. From the fourth day after the
  Peak the woman is infertile until the end of the cycle and intercourse
  is available at any time.]

To Achieve a Pregnancy

Apply the Early Day Rules.

Postpone intercourse until the slippery sensation occurs.

Intercourse should occur over the time of the slippery sensation
and for one or two days after.

For the Postponement of Pregnancy: Rules 1-4