>From the cab ride to the end of the sory, there is no need for major changes.
 That is right on.

The problem rsts entirely with that which goes on before.  The criis over the
pregnancy bit.  The problem is best cxxprssed by the phrase: Too much
solution, not enough problem.  

It seems to me that Ranma didn't want to choose a gender.  Play up that
ambivilance.  Have the fear of hot waer and the fear of pregnancy both be
somewhat unthinking and confused.  Ranma should feel the fears but deperately
try not to think of them  Also, have Ranma terrified that anyone else would
learn the secret.  For if anyone knows, Ranma will have to make the choice of
gender, which Rama DESPERATELY doen't want to.  Ranma knows it cannot be
avoided but it can be deled.  And Ranma will do anything to gert any momet's
delay.  That tension could add to the depth and energy of the story.  Kentaro
  should know something is wrong, but not have a clue.  He should ask and get
evasive answers.  And he shouldn't guess. Ranma should make excuses for
staying female like "I just want be be a woman for you."  Or some such thing.
 But Kentaro  shouldn't believe it.

I recomnd that no one besides Kasumi and Ranma know until the dinner (whuch
probably should be pre-planned, something Ranma can't avoid).  Have that be
the time when Ranma tells them all, either to get it over with or by accident
  That copuld increace the chaos and the drama.  Before then, Ranma should be
constantly, fearfully, and cyptically probing people to determine if Kasumi
told anyone.  Akane's speach about being a woman is important and should be
used ater the dinner, perhapse immediately before going to the cab ride.

Also, have Ranma actually run from the house when Nadoka declares she has no
son.  There could be a tension filled chase, and only after eing
cornmnered/caught would a terrified Ranma learn Nadoka isn't in the killing
mood.  Perhpas Ranma could realize how much protecting the child seems
important during that chase and becom accidentlly aclimate to womanhood.
 (And only realize that during the talk with Akane.)

I also recomed keeping the POV off Ranma as much a possibly after Kasumi
identifies the pregnancy.  There should be a Ranma POV scene invoving the
beginning of the hot-water pranoia, (and if you adopt the chase idea mntioned
above, that POV hould be on Ranma).  But the less we know about exactly what
Ranma's thinking, the more we have to look for clues to Ranma's feelings, the
more compelling the story will be.

Finally, I hope that either you or the other author of this series,
WebDragon, does continue on with at least one story.  For I think it would be
intersting to explore how a young girl would feel growing up with a mother
who's a man on occasion. 

I hope this was helpfull.  I look forward to seeing Serendipity revised and
polished.