Day 3

A woman’s menstrual cycle is measured from the first day of her period (blood flow, not spotting), so Cycle Day 3 is the third day of her period. When a woman is undergoing a fertility work-up, Cycle Day 3 is the day she has blood work performed to check the levels of three important levels: follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2). FSH is secreted by the pituitary gland. It stimulates the production of estradiol (estrogen) and eggs (oocytes) during the first half of the menstrual cycle. The eggs begin to grow in their individual fluid sacs, or follicles, which is the first step in the ovulation process. High levels of FSH are an indication of poor ovarian reserves; in other words, the quality and quantity of eggs is low. 

  • Follicle Stimulating Hormone (FSH) – Secreted by the pituitary gland, FSH helps stimulate the ovaries to cause an egg to mature.
  • Luteinizing Hormone (LH) – Also secreted by the pituitary gland, LH levels often rise when a woman is mid-cycle, helping ovulation to occur.
  • Estradiol (E2) – E2 is an extremely important form of estrogen that’s secreted by the ovaries. It is the primary female reproductive hormone.

Day 3 testing refers to a fertility test that women undergo on the third day of their menstrual cycle. This will involve bloodwork, basic ultrasound assessment, and other types of analysis in order to assess issues pertaining to fertility and infertility.


Day 3 testing allows fertility specialists to really understand the nature of a patient’s health and wellness as well as her current reproductive needs. The blood work allows for a deeper-level analysis while the ultrasound provides specialists with a good understanding of the health of the patient’s reproductive organs.