I've never taken it as a medication. But, it is the natural hormone in the follicular stage that is responsible for producing cm. If you have low estrogen, it would stand to reason you would have sparse or poor quality cm. I used PreSeed when on Clomid. I did get pg, but I don't know if it was a determining factor.
In addition to Pre-Seed, you can also try taking Evening Primrose Oil. I am also on Clomid and found my cm to be very sparse. So, I started taking EPO and in the first cycle using it I saw big difference in my cm. Hope this helps!!