J.A.
I nursed both of mine until 20 months or so, my period came back at 8 months with the first and 10 months with the second. Just keep nursing, add extra pumpings in between regular feedings if you feel your supply has dipped. I just read in "THe Nursing Mother's Companion" that the dips in supply usually only last for the first few periods(and it only happens for a few days prior to the period), though it can last longer. It said Calcuim and magnesium supplements may help. You may want to check out the book from the library or google it.