Leaking

Everytime they've tested me it says it's not amniotic fluid. But with the other 2 pregnancies I've had I've leaked around 27 or 28 weeks. Well I'm 27 weeks and 4 days , and have the worst back pain ever and when I get on all fours to try to ease the pain it's like I leak something cause my underwear end up wet. Not like soaked. But spots of wetness. Anyone else have this happen?