Trigger shots can definately be useful with clomid. They are mostly done in conjunction with IUI. That is how we got the Froggy and likely how her sibling will come if there is one. Whether or not it is specifically helpful in your situation or not I cant speak to but here are a couple of links.

http://www.webmd.aol.com/infertility-and-reproduction/guide/fertility-drugs
http://www.merck.com/mmhe/sec22/ch254/ch254c.html