K.H.
I breast fed both my children, and my youngest for much longer than my oldest. Mother nature presented me with her priceless gift after about the 4th month after my oldest, but not until the 13th month after my youngest was born. Everyone's body is different (and can be different after each pregnancy), so if it persists, you should just check with your dr. to be on the safe side...especially if you experience any issues to accompany what you've expressed here. Flu like symptoms could be a sign of infection somewhere (of course, with flu season upon us it might make it harder to discern). Ehhh, better safe than sorry with a little baby to take care of.