The Lactational Amenorrhea Method is a well documented form of contraception.
http://www.waba.org.my/specialpages/lam/lam.htm
There are some simple guidelines to using it:
1 Do not use if your baby is over six months.
2. Do not use if your periods have returned.
3. Do not use if you are not exclusively breastfeeding.
4. Do not use if the feeds are not at the breast.
The method is 98.8% safe – similar to the pill.
If your periods return before six months it is likely that your first period is an unfertile period and you should use it as a sign that you could get pregnant with the next one which is usually four weeks later.
If your first period is after six months there is a much higher likelihood that this first period will be fertile and it is possible to get pregnant without having a period. (I know lots of mothers who this has happened to and most have a 21 to 27 month gap between babies.)
If you are not directly breastfeeding for each feed but pumping and supplying expressed breast milk for some of the feeds then the method reduces its protection to about 75%.
Direct breastfeeding stimulates that breasts better than pumping and the hormone levels are much higher when you breastfeed than when you pump. The different hormone levels is usually the reason why mothers find long term pumping hard.
Best wishes,
SARAH