Endometrium thickness

Does clomid really thin out the lining more than injectables? The literature says that it only does this when taken on its own, but not when supplemented with estrogen.
From Dickey and Holtkamp, Human Reproduction Update 1996, Vol. 2, No. 6 pp. 483–506

Does endometrium thickness affect IUI outcome? Yes, significantly (p < 0.01). IUI birth rates per cycle for endometrium thickness at time of HCG trigger:

Regimen	6 mm or less	6 to 8 mm	8 mm or greater
Clomid	0%	7.0%	14.0%

From Dickey and Holtkamp, Human Reproduction Update 1996, Vol. 2, No. 6 pp. 483–506

At my scan yesterday (CD14) my endometrium thickness was 6.9 and my dominant follicle measured 19.6. We triggered last night, and the IUI is today. Looking over my last three cycles, I analysed my data and saw that, while Menopur thickened my lining more quickly, I also ovulated earlier at CD9. For all three cycles, my lining is around the same thickness right before ovulation, and it is far below average. At least this time it's above 6, which means we have a shot.