test levels and estrogen levels sort of strike a balance (whatever that is in your specific case via a negative feedback loop).
Clomid works to raise LH (indirectly FSH). It does so by blocking estrogen in the brain (pituitary). The pituitary senses less estrogen, and makes more LH. More LH means Leydig cells produce more testosterone.
If I remember it also has some impact on the net motile number of the swimmers --but I could be wrong/