Progesterone test

A mid-luteal progesterone test is taken roughly seven days before the next period is due — day 21 in a 28-day cycle, but later in longer cycles. A clearly raised level indicates that ovulation has occurred. If the timing was wrong for your cycle length, a low result may simply mean the test was taken too early or too late, so check the timing before concluding anything.

Also known as: day 21 progesterone, mid-luteal progesterone, ovulation blood test

Last reviewed: 8 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.