An Easy Guide To Your Cycle: How Hormone Levels Shift Each Month
Whether you’re trying to conceive, considering egg freezing, or just want to understand your body better, getting to know your hormones throughout your menstrual cycle is one of the most powerful things you can do.
Your body isn’t the same every day and your hormone levels shift week by week, affecting everything from energy and mood to fertility and libido.
In this article, we’ll break down how key fertility hormones behave during your cycle and what they’re trying to tell you.
Week 1: Menstrual Phase (Day 1–5)
Your cycle starts on Day 1 of your period. At this point, your hormone levels are at their lowest.
What’s happening:
Your uterus sheds its lining → that’s your period.
Hormones like estrogen and progesterone are low.
You might feel tired, crampy, or emotional (thanks to the hormonal drop-off).
Hormones involved:
FSH (Follicle Stimulating Hormone) begins to rise to prepare follicles (aka potential eggs) for ovulation.
AMH (Anti-Müllerian Hormone) remains fairly stable - it reflects your egg reserve, not a daily fluctuation.
Testing tip: This is the ideal time to test FSH and estradiol to evaluate your ovarian reserve.
Week 2: Follicular Phase (Day 6–13)
As your period ends, your body starts prepping for ovulation.
What’s happening:
One follicle becomes dominant and matures.
Estrogen rises sharply as the follicle grows.
You might feel more energized, clear-headed, and social.
Hormones involved:
Estrogen helps thicken the uterine lining for a possible pregnancy.
FSH supports follicle development.
LH (Luteinizing Hormone) stays low, for now.
Estrogen levels can be a sign of follicle development and ovarian health. Lower-than-normal estrogen might indicate poor egg growth or hormone imbalances.
Week 3: Ovulation (Day 14–15)
This is the main event. Ovulation usually happens mid-cycle, but can vary based on your body and cycle length.
What’s happening:
A surge in LH triggers ovulation.
Your ovary releases a mature egg.
Your fertility is at its peak.
Hormones involved:
LH surges dramatically and quickly drops after ovulation.
Estrogen peaks, then dips.
Testosterone also rises around ovulation increasing libido.
Want to time ovulation? LH tests (ovulation strips) can catch this spike, and tracking cervical mucus helps too.
Week 4: Luteal Phase (Day 16–28)
After ovulation, your body prepares just in case you’re pregnant.
What’s happening:
The empty follicle becomes the corpus luteum and starts producing progesterone.
Your uterine lining thickens even more.
If no pregnancy occurs, hormone levels drop and your cycle restarts.
Hormones involved:
Progesterone is the star here - it calms your system, raises basal body temperature, and prepares the body for implantation.
If you’re pregnant, progesterone stays high. If not, it drops, triggering your period.
Low progesterone may be linked to short luteal phases or trouble maintaining pregnancy. A blood test around Day 21 can assess your levels.
Why This Matters for Fertility Awareness
Understanding your hormone patterns can help you:
Pinpoint ovulation and fertile days
Understand PMS or cycle-related symptoms
Identify hormonal imbalances like PCOS, low estrogen, or thyroid dysfunction
Time fertility testing for more accurate results
Start conversations with your huisarts or fertility specialist
Want to Check Your Hormone Levels?
You don’t need to wait for a GP appointment or clinic visit to learn what’s going on. At-home hormone test kits in the Netherlands make it easier than ever to test key hormones like:
FSH + LH (cycle health and ovulation)
Estradiol + Progesterone (estrogen and luteal phase support)
TSH (thyroid health)
ready to check your fertility?
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ready to check your fertility? 〰️
Final Thought: Your Body Isn’t Random - It’s Rhythmic
You’re not "moody" or "inconsistent" - you're cyclical. Understanding how your hormones shift each month is the first step toward smarter fertility planning, better energy management, and feeling more connected to your body.
