I am on Gynera now, a type of OCP. I started doing some research on the reason and found the below :)
Convenience is a factor that contributes to a woman's general peace of mind and health. But from a clinician's point of view, the ability to time the IVF process is also crucial.
Dr. Pinkas explains, "One of the main drawbacks in treating infertility is timing a woman's body with the clinic's schedule, so we can get as many mature eggs as possible. IVF clinics can be extremely busy. With a proven and safe method for timing when a woman can undergo therapy, there is a lot less stress placed on the physicians' shoulders too."
Normally doctors start the IVF treatment from the moment a woman gets her period. But the use of birth control pills, for 10-14 days after a period, allows the treatment to be adjusted without compromising the "ovarian response to stimulation," says Dr. Pinkas. This way, egg-harvesting can fall on a date mutually convenient to both the clinician and patient.