The ReceptivaDx test was originally validated in natural cycle biopsies collected 7-10 days after ovulation. The natural cycle biopsy provides a significantly lower expense to the patient by removing the need for costly medications used in mock cycle biopsies. If a mock cycle biopsy is preferred by your provider, ReceptivaDx has now been analyzed in over 15,000 mock cycle biopsies and can be performed safely without concern. Providers are reminded that 5 full days of progesterone administration (120 hours) must be onboard to obtain accurate results. Chances of a false negative can occur if protocols are not properly followed. While other endometrial biopsy tests for timing purposes suggest day 5 biopsies in their protocols, we recommend day 6 or day 7 at the earliest to obtain an accurate BCL6 result.