Hi S.,
I second the recommendation of NFP as taught by the Couple to Couple League (CCL)! They teach you about "Ecological Breastfeeding", a type of nursing which naturally gives women an average spacing of 2 years between births, due to the lactation amenorrhea of 14.5 months it provides (on average--each woman is different). They also teach you how to know when your fertility returns. You can ovulate before your first warning period--this happens 15% of the time. It happened to me, but I knew from my signs that my fertility was returning. My husband and I decided not to postpone and our third was conceived when my second was 14 mos. and before my cycles began. I had no cycles for almost 4 years! This helps reduce breast cancer, and the normal lack of cycles (from lactation amenorrhea) retains your iron reserves (so you have more energy to care for baby!). We've spaced all our children this way (and even extended the 2 yrs. with systematic NFP). We're so happy to be free of all artificial BC in our marriage (it felt like gearing up for war, not love!).
This is from http://ccli.org/nfp/ebf/summary.php:
Summary of Ecological Breastfeeding and Natural Child Spacing Program
Basic Principles
1. Frequent and unrestricted nursing is the primary factor in producing natural lactation amenorrhea and infertility. (Lactation amenorrhea is the absence of menstrual periods due to breastfeeding.)
2. Ecological Breastfeeding (EBF) almost always provides this frequent nursing and natural infertility. It is that type of baby care which follows the natural mother-baby relationship. It avoids the use of mother-substitutes, such as bottles and pacifiers; it follows the baby-initiated patterns. EBF is the norm and offers many built-in benefits, one of which is extended natural infertility. In essence, a lengthy postpartum amenorrhea is the expected norm.
Ecological Breastfeeding: The Early Months
This phase almost invariably produces natural infertility as long as the program is complete. Phase I usually lasts six months. The key to natural infertility is frequent and unrestricted nursing. The following Seven Standards help to ensure this frequent nursing.
1. Do exclusive breastfeeding for the first six months of life; don't use other liquids and solids.
2. Pacify the baby at the breast.
3. Don't use bottles and pacifiers.
4. Sleep with the baby for night feedings.
5. Sleep with the baby for a daily-nap feeding.
6. Nurse frequently day and night, and avoid schedules.
7. Avoid any practice that restricts nursing or separates mom and baby.
Ecological Breastfeeding: Later Months
At around six months of age, the baby will start taking solids or liquids other than breast milk.
Aside from Standard #1, exclusive breastfeeding, the other six standards will remain operative until the baby gradually loses interest in breastfeeding.
This time is one of very gradual change in which the amount of nursing is 1) not decreased at all at first, and 2) lessened only gradually at the baby's pace. The time of natural infertility that a woman can achieve at this time is frequently longer than the first six months if the EBF program is followed with continued frequent and unrestricted nursing, although this varies from woman to woman.
Chance of Pregnancy:
The First 6 Months. The first 8 weeks postpartum for the exclusively breastfeeding mother are so infertile that in 1988 scientists agreed that any vaginal bleeding during the first 56 days postpartum can be ignored for determining amenorrhea or fertility for the exclusively breastfeeding mother. This rule would also apply to the EBF mother.
During the first 3 months postpartum, the chance of pregnancy occurring
is practically nil if the EBF mother remains in amenorrhea.
During the next 3 months postpartum, there is only a 1% chance of
pregnancy if the EBF mother continues to remain in amenorrhea.
After 6 Months. For the nursing mother there is about a 6% chance of pregnancy occurring prior to the first menstruation. This assumes no fertility awareness and unrestricted intercourse. This risk can be reduced to close to 1% through the techniques of systematic natural family planning — observing the signs of fertility and abstaining accordingly.
About 70% of EBF mothers experience their first menstruation between 9 and 20 months postpartum. The average return of menstruation for EBF mothers is between 14 and 15 months.
Natural Spacing by Breastfeeding Alone
For many couples who desire 18 to 30 months between the births of their children, Ecological Breastfeeding should be sufficient.