Ay, that's the mucus plug! Hindi pa talaga yan sign ng active labor, kasi pwedeng lumabas siya weeks pa bago magstart ang actual contractions, a few of us moms experienced it like that din, nag-panic kami thinking delivery na agad hehe. Best to call your OB lang para ma-confirm kung lahat okay at para alam mo na what to expect in the coming days, lalo na since you're already in the home stretch ng pregnancy!