I will try to explain what I have learned--but it is pretty complicated. It is not normal to have a menopausal FSH (follicle stimulating hormone) while nursing. Do you have a high FSH? What is the number? I would be able to better answer your question if I knew your exact test results.
Some women do have very low levels of estrogen when nursing--could even be as low as menopausal levels...although that is pretty rare--but it does happen. But if you have a normal FSH and LH, but just meno-leveled estrogen levels then you are probably fine. But if your FSH levels are in the meno range then that is in no way "normal".
As I said before, I was pretty shocked at my diagnosis. I had no risk factors for POF (no auto-immune issues, previous cancer, chromosomal problems--just infertility in my past). I soon learned that the majority of women don't have these risk factors that have POF. And I was actually pretty darn lucky that I had done infertility treatments earlier in my life and had 2 children before my diagnosis--most women who have POF are diagnosed just as they are starting to try and get pregnant...or even sooner in their teens.
The way that I dealt with my condition was to reasearch it to death. I spent hours online looking up info on it, and saw two fertility specialists in our area (at UCSF and Stanford Infertility) to see if there was any way my body could "snap out of it" or I could do fertility treatments. Unfortunately the answer was *no* to both questions. Well, I could have done egg donation, but at that point we were ready to move on to adoption--which has been a huge blessing for us.
I also had a phone consult with Dr. Larry Nielson at NIH (National Institutes of Health) as he is doing a huge study on POF. I quizzed him about if my long term nursing could have somehow "caused" my POF--either temporarily or permanently. He said an emphatic "NO" to that. I worried because I did nurse my daughter for almost 3 years and weaned just prior to my diagnosis. He said that my nursing was probably surpressing some of my meno symptoms, and that is why the hot flashes came charging in when I weaned Samantha. He also encouraged me to be retested--which I did 5 times...and my FSH was always very high in the menopausal range...69-100+. At one point it dropped to 39, but that is still firmly in postmeno range.
If you have any other questions please feel free to ask. Here is some info on hormone levels while lactating:
General Summary of Hormonal Changes(1)
6.2. Breast-feeding is associated with high plasma concentrations of prolactin, at least at the onset of lactation, the levels correlating to some extent with the number of suckling episodes 12). The prolactin response to suckling declines with time post-partum, but if suckling frequency is maintained at a high level basal levels may well remain above normal for 18 months or more (2, 3) (see fig. 15).
Blood levels of follicle-stimulating hormone FSH) are necessary for ovarian follicular growth and development, and quickly return to normal menstrual cycle levels within a week or two post-partum. At no stage during lactational amenorrhoea do FSH levels appear to be inadequate for ovarian function. Pituitary levels of luteinizing hormone (LH) are very low immediately postpartum, but by 15 to 20 days blood levels have increased significantly and remain throughout lactation on the lower side of normal.
During lactational amenorrhoea in fully breast-feeding women, the response of LH to GnRH stimulation is diminished, while the FSH response is normal. In the same situation, women fail to show a positive feed-back response, with an increase in LH and FSH to exogenously administered estrogen, whereas they show an enhanced negative feed-back effect with prolonged suppression of LH levels in contrast to normally cyclic women. In lactational amenorrhoea, ovarian estrogen and progesterone secretion is below normal, and is equivalent to that seen in post-menopausal women in spite of normal levels of FSH.