Good project

 Prostaglandins cause luteolysis and embryonic death. it is better to improve the progesterone secretion from a poor corpus luteum with the administration of HCG or GnRH especially on days4, 5, 6 or days 10, 11, 12 post AI or Natural service.

Dear Mehrajuddin.

It's a good point you made here. Here is a paper from colleagues. They had similar project, maybe it could be helpful to you. 

Good luck with your project.

Regards,

Jiri