Heather,
The breast has an axillary tail, called the tail of Spence.  This is
usually what the mother notices as lumpiness in the armpits.  If the
lumps are very large, perhaps they are supernumerary breasts.  The axilla
is a common place for extra breasts.
        John and Sheila Kippley write in The Art of Natural Family
Planning that "Typically, the basal temperatures for the nursing mother
tend to be erratic and somewhat lower than usual."  They reccommend that
breastfeeding mothers begin to take their temperatures again only after
there is a return of mucous or menstruation, or a decrease in nursing or
the start of solids for moms who have had early return of menses after a
previous baby started solids.  Things that increase the basal temperature
include increases in the basal metabolic rate (regulated by the thyroid
gland) and secretion of progesterone by the corpus luteum after
ovulation, and placental hormones during pregnancy.  In an
amenorrheac (sp?) mother of a 7 mo old, pregnancy would be unlikely
unless: the mother were not exclusively breastfeeding, solids were
introduced rapidly, or the baby suddenly began to sleep through the
night.
--
Catherine Watson Genna, IBCLC  NYC  [log in to unmask]