menustration while breastfeeding
My experience with both of my children was that I did not resume menustrating AT ALL until I had completely stopped nursing. Even when I was only nursing once or twice per day (towards the end) I still did not get my period.
At that time, I was not into regular exercise so I think exercise would not be the cause of this. When one is nursing, I am not sure if no periods is really considered ammenorhea since it is the hormones that cause it not excessive exercise or too low bodyfat. Feel free to correct me if I am mistaken.
Also, for me, breastfeeding took the weight off like magic. I ate what I wanted, hardly exercised (I know - bad) and still dropped the weight. In fact, 5 months after my daughter was born, I weighed 15 lbs. less than the day I found out I was pregnant. It worked that way for my second baby too. For me, having babies was a good thing for my body (except for the c-section scar etc.).
Had I exercised back then like I do now, I am sure I would have even had better results. Oh well, hindsight is 20-20 they say and now I have the muscle to speed my metabolism instead of milk production.
Kim