Still no progress -- Evening Primrose Oil

𝓂𝒾𝓁𝓀𝓎 𝓂𝒶𝓂𝒶 • 🌿adelynn 9.14.16 & baby koston 12.31.18🌱
I'll be 38 weeks on Tuesday and we still haven't had any progress made with dilation or effacement. Yes, I know there's still plenty of time lol. But my doctor mentioned Evening Primrose Oil today and said that next week I could start using it but I'm not sure how it works or how to use it. If any of you ladies have used it before, what worked for you?