I use Bio Oil now but during the first two trimesters I used the Palmers Cocoa Butter.
Unfortunately it has done me no good as I have just started to get some nice stretchies in the last 2 weeks I thought I'd be lucky as my Mum never got them but nope guess being super skinny pre pregnancy has its disadvantages.

I def recommend the Bio Oil though, its a bit greasy at first but I notice a difference in the visibility of the stretchies right away!