Alesse is a somewhat new, heavily marketed combination pill that they claim
has the lowest amount of estrogen on the market.  I personally switched from
the mini-pill over to Alesse when my nursling was about 22 months old.  There
was no noticeable decrease in milk supply at that point.  But you didn't
mention how old the baby was in this case.  (the mini-pill also did not reduce
my supply, when I started it 6 months pp)  Side note:  I do buy the fact that
it is low estrogen, because I became pregnant after not missing a single one!
Big surprise!
Chris Willison
Bowling Green, KY