Ditto to malama....Many things can give you a false postive-semen and urine included. It is good that the microscope test was negative. She is smart to ask you to wear a pad, and just collect more information before taking action. If you are leaking there will be distict gushes in small quanities through the day, esp when you cough or the baby moves.
It is VERY hard to diagnose when the water broke but is just trickling...This kind of break is called a "high leak", meaning there was a small tear in the bag so water comes from deep and high in the uterus. It is a big contrast to they way water breaks more often, which is that the bubble right over the cervix/over the baby's head pops followed by a distinct gush. End of pregnancy secretions increase due to more blood flow to the pelvis, making skin cells slough off faster. The resulting discharge is usually milky looking. It tends to get your undies wet just in the front....
She may also want you to watch your tempature, and take Vit C. If the water breaks the concern is that infection may set in soon after since the baby's fortress/ 2-ply hefty bag amniotic sac is not impermeable to germs any longer. An increase in temp would be a concern. I have seen peopel develop uterine infections (then not be able to contract, have a c-section, and a baby with problems from the infection for 7 days) from high leaks, so I never mind having to go through with an early birth if it is really broken, even though it would be a bummer to maybe lose your birth plan, or have a baby earlier than anticipated. It is a time to weigh/risks benefits if it is broken. How your practioner responds will vary according to your region....most agree babies should be well on their way to being born with in 24 hours of water breaking
Just wait and see, if you don't leak more, don't sweat it.