Starting an IVF Cycle

Bri • 2 years TTC- 2 failed IVF, 2 miscarriages. MTHFR, Factor V, High FSH..starting another IVF in November
My husband and I had our IVF consult last month and are thinking of IVF now after 4 failed IUI. How did you all start your IVF cycles? Did you have to wait or did you go straight on birth control with the start of AF? My clinic is confusing as all they said was call at CD1.