If you have negative tests, you are probably ovulating not pregnant. Women have different types or consistency of discharge sometimes its think and pasty sometimes its wet and mucussy. I think you are just ovulating, I get watery cervical mucus right before I ovulate.
You would have to be well into the 2nd trimester to have enough amniotic fluid to leak (and leaking amniotic fluid before delivery is a pregnancy complication) - if you are that far along, a home pregnancy test would be accurate at this point.
More likely options are you are leaking discharge, urine, or semen (if you are sexually active). If you are concerned, make an appointment with your doctor.