Im not sure about drinking it as i took the capsules for both my pregnancies from 32 weeks. my first bub was a nice 8.5 hour labour and i took the capsules right up until the day she was born (40 weeks).
my second i stopped taking the tablets at 36 weeks as i was having constant pre labour and had an irritable uterus, i went on to have a 2.5 hour labour with her (40 weeks). second pregnancy i stopped everything, EPO, sex, RLT (but was still breastfeeding) as they were all contributing to irritable uterus. mostly i think that was due to my pregnancies being close together (within a year)
not sure if thats much help, best of luck..