What happens to oestrogen after ovulation if you become pregnant?
Originally written by Dr Amy Beckley, PhD, founder and inventor of Proov. Updated by femme to remove fixed hormone thresholds that should only be interpreted clinically.
Every menstrual cycle involves coordinated changes in several reproductive hormones. Oestrogen and progesterone both change across the cycle, and their pattern after ovulation differs depending on whether pregnancy occurs.
Before ovulation: oestrogen rises
As follicles develop in the ovary, they produce increasing amounts of oestradiol, the main form of oestrogen during the reproductive years. This rise helps the lining of the womb develop and contributes to the hormonal signal that triggers the LH surge before ovulation.
Urinary E1G tests can reflect a metabolite of oestrogen and may help identify a rising fertile window, but no single at-home reading can prove exactly when an egg will be released.
After ovulation: progesterone rises and oestrogen has a second phase
The corpus luteum
After the follicle releases an egg, it becomes the corpus luteum. This temporary structure produces progesterone and also oestrogen during the luteal phase.
If pregnancy does not occur
The corpus luteum breaks down, progesterone and oestrogen fall, and that withdrawal contributes to the start of menstruation.
If pregnancy occurs
After implantation, the developing pregnancy produces human chorionic gonadotrophin (hCG). In early pregnancy, hCG supports the corpus luteum so it continues producing progesterone and oestrogen.
As pregnancy progresses, the placenta takes over as the major source of these hormones. Oestrogen levels rise substantially across pregnancy and support changes in the uterus, placenta, breasts and other maternal tissues.
Why fixed “implantation ranges” are misleading
Hormone concentrations vary by laboratory method, timing, whether a cycle is medicated and the individual's clinical circumstances. A single universal oestrogen cut-off cannot tell you whether implantation will or will not occur, and it is not appropriate to use a blog threshold to diagnose miscarriage risk.
During fertility treatment, clinics interpret oestradiol alongside ultrasound findings, medicines, follicle development and other results. The expected values can be very different from those in an unmedicated cycle.
What can at-home hormone tracking tell you?
If you are deciding whether to track hormones, temperature or both, our complete BBT tracking guide explains what temperature adds after ovulation, while the at-home hormone test collection shows the current testing options available at femme. For timing conception rather than interpreting one hormone reading, see our guide to the fertile window and chances of pregnancy around ovulation.
Urinary hormone tests can show patterns in metabolites such as E1G and PdG. They can be useful for cycle tracking, but they are not the same as blood hormone tests and cannot diagnose implantation, confirm that a pregnancy is healthy or replace clinical fertility assessment.
Oestrogen after ovulation: common questions
Does oestrogen drop after ovulation if pregnant?
Oestrogen can fluctuate after ovulation, so a brief change should not be interpreted on its own. When pregnancy is established, oestrogen rises over time alongside other pregnancy-related hormonal changes.
Does oestrogen drop after ovulation if you are not pregnant?
Oestrogen has a smaller second rise during the luteal phase and then falls with progesterone towards the end of the cycle if pregnancy does not occur.
Does oestrogen increase after ovulation?
It can. Oestrogen does not simply rise before ovulation and then disappear. A second, smaller luteal-phase rise is part of the normal cycle pattern.
Can an oestrogen or E3G reading tell you whether implantation happened?
No single home oestrogen or E3G reading can confirm implantation or show whether an early pregnancy is healthy. A pregnancy test detects hCG and is the appropriate home test for pregnancy.
Does oestrogen drop after ovulation if pregnant?
It can fluctuate briefly after ovulation, including in cycles that result in pregnancy. A single dip does not show whether implantation has occurred. If pregnancy becomes established, oestrogen rises over time, so the overall pattern matters more than one E1G, E3G or blood oestradiol result.
The bottom line
If you are trying to conceive, hormone charts make more sense when they sit inside the bigger preconception picture. Our guide to health before pregnancy covers the evidence-based basics beyond cycle data.
Oestrogen rises before ovulation, remains active alongside progesterone after ovulation, falls with progesterone if pregnancy does not occur, and rises progressively when pregnancy is established. The pattern matters more than trying to compare yourself with one internet number.
