Is Ovral G Effective In Bringing On Periods?

Hi doctor i m nidhi. I m going for ivf as the doctor called in 12 april 2011. My menses started from 22.03.2011. My doctor has given OVRAL G tablet to start from 26.03.2011 to 14 th april.will this tablet start my menses from 14 april. Bcoz hormonal injection will start from 12 april. Docs called us on 12 april to 4 may for ivf. YYYY@YYYY