Thick, creamy urine indicates that your rabbitis getting too much calcium. Sometimes they'll get urine thatlooks like this once but will be fine the rest of the day and you won'tsee it again for weeks. If you see it more often, you shoulddefinately decrease her calcium intake. If she is fully grown(usually over 6 months), switch her to a timothy based pellet insteadof alfalfa. Adult rabbits should not be fed alfalfa unlessthey are breeding or having trouble maintaining their weight.
Is your doe spayed? If not, has she ever been with a male orcaged directly next to one? The can "have fun" through thecage bars. If she is spayed, she probably is experiencing afalse pregnancy. If she is not spayed, I'd prepare for babiesjust to be safe.