The best day to collect your serum hormones sample is during the progesterone peak of the luteal phase, between days 19-22 of a 28-day cycle or ~7 days after ovulation (if tracking). For longer cycles, add the number of days beyond 28 days (example: collect days 21-24 for a 30-day cycle). In a similar manner, subtract for shorter cycles (example: collect days 17-20 for a 26-day cycle).
When should I collect my Serum Hormones sample?
Adair