Hindi necessarily, mama, mucus plug and cervical opening ay iba-iba, kaya kahit may discharge ka na parang mucus plug, baka hindi pa fully dilated ang cervix mo (ang OB lang talaga makikita yan during IE). Normal discharge pa rin pwede kahit starting na mag-open ang cervix, so walang one-size-fits-all sign dito, best talaga to ask your OB bukas na lang since you're already at 38 weeks, para sure ka na. A few of us moms nagsabi na sobrang variable lang talaga from person to person, kaya don't stress too much about trying to read the signs yourself, ang internal exam is really the only reliable way to know.