Fetal fibronectin test... Anyone get a positive?

Emily • My son Nolan passed away after birth. Now we have to wait 9 months to start trying due to complications obtained from the c section... preventing until july, then back on the trying train.
Jest went in with pain on one side (not personally thinking preterm labor) and everything checked out fine. Sent home with radiating hip pain. But they called to say the fft test they did came back positive. Does anyone know anything about it or have any experience with this? I'm only 28 weeks