Taking a blood test during ovulation is a way to check a woman's fertility. During ovulation, a woman's ovaries release a mature egg, which is then transported to the uterus through the fallopian tube. If a woman's eggs are fertilized during this period, she can become pregnant.

Ovarian hormone is a hormone that promotes eggs, and its concentration in a woman's blood changes with her menstrual cycle. Through blood tests, doctors can determine a woman's ovarian hormone concentrations and thus determine when she is ovulating.

Uterine is also an egg-stimulating hormone that changes with a woman's menstrual cycle. Through blood tests, doctors can determine a woman's uterine hormone concentrations and thus determine the state of her uterus, including whether it is at its most fertile.

By using a blood test to determine when a woman is ovulating, doctors can better predict a woman's fertility and help them better plan for pregnancy. At the same time, this blood test can also help women understand their fertility so that they can better deal with possible health problems.