Aw, walang nakasakay pa dito sa primrose oil question mo! Honestly, from my circle of mum friends, a few of them tried it towards the end ng pregnancy kasi daw nakakatulong sa cervical ripening at dami-dami ng stories na effective, pero ang timing talaga ng labor ay so unpredictable, iba-iba ang experience ng bawat mama, kaya hindi ko ma-guarantee kung ilang days talaga bago mag-labor. Better check with your OB about this one para safe ang approach and dosage for you specifically, because pregnancy is really such a case-to-case thing!