Day 3 of Menstruation: Early Follicular Phase
On day 3 of your period, you are in the early follicular phase of the menstrual cycle. 1, 2
Understanding the Early Follicular Phase
Day 3 falls within the menstrual/early follicular phase, which represents the beginning of the menstrual cycle when hormonal levels are at their baseline. 1 This phase is characterized by:
- Active menstrual bleeding that typically lasts 3-7 days from cycle day 1 3
- Low estrogen and progesterone levels as the previous cycle's corpus luteum has regressed 4, 5
- Rising FSH levels that begin stimulating a new cohort of follicles for the upcoming ovulation 4
Hormonal Characteristics at Day 3
The early follicular phase (days 1-6) is the optimal time for baseline reproductive hormone assessment because:
- FSH and LH are at baseline levels, making this the standard timing for fertility testing 1
- Estrogen levels are low as follicular development is just beginning 2, 5
- Progesterone remains low following the regression of the previous cycle's corpus luteum 4
The American College of Obstetricians and Gynecologists specifically recommends day 2,3,4, or 5 for blood testing to assess baseline reproductive function. 1
What Happens Next in Your Cycle
Following day 3, the follicular phase continues with:
- Progressive follicle growth stimulated by rising FSH levels 4
- Gradual increase in estrogen as the dominant follicle develops 2
- Ovulation typically occurring around days 12-14 in a standard 28-day cycle, though this varies significantly with cycle length 2
Clinical Relevance
Understanding that day 3 represents the early follicular phase is important because:
- Baseline hormone measurements taken on day 3 serve as reference points for assessing ovarian reserve and reproductive function 1
- Cycle length variability primarily stems from differences in follicular phase length, while luteal phase length remains relatively constant 4, 3
- Emergency contraception considerations: If hormonal contraceptive pills are missed during the first week (which includes day 3), emergency contraception should be considered if unprotected intercourse occurred in the previous 5 days 6