Clomid with IUI vs. Clomid with TI

So I just finished my first round with clomid and the Ovidrel shot with TI and got a BFN. I started with 50 MG of Clomid CD 3-7 without any follicles, so they put me on 100 mg CD 11-15 and I know I had at least one large follicle. So since this wasn't successful should I go another round with the 100 mg at the beginning of the cycle and the trigger shot and timed intercourse OR do the clomid 100 mg, trigger and IUI? Is it really a huge difference with success rates?