2. The basic biology of the female that produces
conditions permitting pregnancy would argue that either
Ranma turns female in a highly 'fertile' state (thereby
bypassing all normal physiological conditions of ovulation
ect.); or the male Ranma, somehow, continues the basic
monthly cycles of a female even when he isn't.
        If neither is the case, then the female Ranma
wouldn't become 'fertile' (i.e. an egg in place to
fertilize) for some 21 days or so.  This would kinda
slow down the story a bit.

you missed one other posibility, that of ovulation ocuring 
sequentialy bit by bit whenever he is female, so when he isnt nothing 
happens and when he is normal processes continue from where they left 
off.   

shade and sweet water 
skywise
kschultz1@isd.net
skywise@juno.com
Warped Reality 1-9(mine)
The Circe Prodject
Mark Latus's storys (all)
Sailor Moon V