pom in heat

Question
i believe my pom is in heat? her thing is swollen. is this normal? how long does this last. and she seems sad .

Answer
The swelling of the vulva is the first stage of the heat cycle.  A bloody discharge should start in a few days tapering off and ending in about 3 weeks.  Be extremely careful to keep her away from males.  If she is less than a your old, she is not ready to bear a litter.  If you have to ask a question like this, you are not ready to be breeding dogs.  There is no end of misery resulting for the uninformed keeping intact dogs.  Either do some serious study on dogs, or get her spayed as soon as a vet will do it.