Bio oil during pregnancy for stretch marks?

Has anyone used it? I hear it's supposed to help really well in preventing them, and so far I believe cocoa er, Vitamin E, Baby oil, and palmers tummy er have been helping me out alot, but 1 stretch mark did make it's way onto my stomache, not bad I figure since i'm 33 weeks pregnant, and VERY prone to stretch marks, it even came in already faded, with just a small tinge of pink, but can anyone tell me their experiences with Bio oil? I hear from all the reviews that it's supposed to be some miracle oil.