
Fertility
Low progesterone symptoms, and how to track for success
Eloise Edington | 20 Jul 2022
Progesterone is crucial for regulating the menstrual cycle, and whole-body health. But in fertility terms, it has a star role to play. It prepares the uterus for pregnancy, and works alongside other important hormones, like estrogen, to balance your body’s complex processes.
Struggles to conceive and a history of miscarriage or early pregnancy loss are key symptoms of low progesterone, but so are irregular cycles, spotting, mood changes, and more.
An at-home progesterone test, to cut the guesswork
To give you the lowdown on progesterone, we’ve teamed up with Inito, the world’s only at-home device which allows you to measure estrogen and luteinizing hormone (LH) levels to predict your fertile days, and progesterone to confirm ovulation.
The best bit – it’s all available on a single device, connected to your smartphone.
Keep reading Inito’s 101 on the symptoms of low progesterone, and how their at-home testing options could change up discussions with your fertility doctor, or team.

What is progesterone?
Progesterone, often known as the pregnancy hormone, is secreted by your adrenal cortex and ovaries. It plays a primary role in early pregnancy, because it prepares your body for healthy implantation (when an egg travels along the fallopian tube and burrows deep into your uterus).
So it’s crucial for pregnancy (and that all-important two week wait) but also for a healthy menstrual cycle. Before we cover the most common symptoms of low progesterone, here’s a quick picture of how this amazing hormone works, day-to-day:

Ovulation
Every time you ovulate, your body releases an egg from a follicle inside your ovary. Once its job is done, the follicle seals and forms the corpus luteum. This temporary mass of cells produces progesterone during early pregnancy.
Menstruation …
If the egg doesn’t implant in your uterus, the corpus luteum breaks down and progesterone levels start to drop – if you’re measuring with Inito, you’ll be able to see this shift in your personalized chart results.
This drop in progesterone is what triggers your menstruation, and your period.
… or implantation
Or, if the egg does implant, the corpus luteum continues producing high progesterone levels (which you can see on a tracker like the Inito fertility monitor). This is a crucial part of supporting early pregnancy.
8-10 weeks after implantation
By 12 weeks into pregnancy, and often before, your body’s developing placenta takes over progesterone production until your baby is born.
There’s no question, progesterone is important. Especially in early pregnancy. It helps prepare your body for implantation, and for staying pregnant once the egg has found its comfy home. And for that reason, it’s a key part of preventing early miscarriage.
Symptoms of low progesterone
So, what should we be looking out for if we suspect low progesterone levels? Or, if we’re just trying to optimize for general fertility/menstrual health?
Key signs of low progesterone include:
- irregular periods and/or short cycles
- spotting just before your period
- heavy periods, linked to estrogen dominance
- a short luteal phase
- early pregnancy loss, or miscarriage
- mood changes (including increased anxiety and/or depression)
- disturbed sleep
- breast tenderness
- headaches
- weight gain linked to fluid retention (in rarer cases)

These are your tell-tale symptoms of low progesterone. And ones you can definitely round-up and bring to your next gynecologist check-in, or your fertility team. Let’s unpick them a bit now, and talk about what low progesterone levels can look and feel like, day-to-day:
1. Irregular periods, shorter cycles and spotting
You need to ovulate before producing progesterone. If you aren’t ovulating (which is the case for around 40% of women experiencing fertility issues), your period may be irregular, come early, or you may skip it altogether.
Spotting can result from a weakened uterine lining – remember, this lining is literally falling away as you start your period. Progesterone supports your uterine lining, so as levels start to fall (or if they never get very high), spotting can be one of the most common symptoms of low progesterone.
Some spotting is normal before your period, because progesterone levels will drop as expected, but two or more days of spotting before you’re due may be a discussion point with your doctor.
2. Heavy periods
Your hormones need to perform a complicated dance every month, to create the right balance for a healthy cycle. High estrogen and low progesterone levels – or hormonal imbalance – can cause the uterine lining to thicken. And when shed during menstruation, this can cause heavier periods, more prone to clotting.
Heavy periods are one of the most common symptoms of low progesterone – if you’re concerned, do speak to your doctor or healthcare provider about next steps and diagnosis.

3. A short luteal phase
The luteal phase makes up the second half of your menstrual cycle. It starts just after ovulation and carries on right up until your period arrives.
Ideally, the luteal phase lasts about 12-14 days. If yours is less than this, speak to your doctor about a possible luteal phase defect, which can be caused by low progesterone levels.
4. Early pregnancy loss, miscarriage and conception struggles
Sadly, low progesterone in early pregnancy can increase your risk of miscarriage. As we’ve covered, your body requires elevated levels of progesterone for key processes in your menstrual cycle, and for healthy implantation.
So low progesterone in pregnancy, before the placenta has taken over on production duties, can be a factor if you have a history of early miscarriage, or are struggling to conceive.
5. Mood changes
From depression and anxiety to general irritability, mood changes are hard to pin down, but can be key symptoms of low progesterone in the build up to your period.
Again, it’s about a balance in your hormones. Studies show that increased levels of progesterone (which is a relaxing hormone) in your luteal phase, versus estrogen, can cause lower levels of aggression, irritability and other mental health issues, including depression.
6. Disturbed sleep
Do you find it more difficult to get quality sleep in the second half of your cycle? As we’ve covered, progesterone is a relaxing, usually sleep-inducing hormone, and lower levels could contribute to a more ‘wired’ state at bedtime.
For some women, the brain actively needs permission to start shutting off. And hormonal imbalances, like a lack of progesterone, can aggravate this.
7. Breast tenderness, headaches and weight gain
These other physical signs can be symptoms of low progesterone, which is often associated with increased fluid retention. Headaches can also be triggered by a drop in hormones – you’ve probably heard of the ‘hormonal headache’.
Try an at-home progesterone test
Knowing these key symptoms of low progesterone helps get the ball rolling. But tracking your levels can be a game-changer, helping you bring invaluable information to every fertility appointment.
If you’re tracking at home and building up a picture, it leaves so much more time with your doctor to chat through the results. You can build a picture of your fertility health much more quickly.
Track your hormones with Inito

We love the Inito fertility monitor for exactly this reason. Whether you need an estrogen, luteinizing hormone (LH), or a progesterone (PdG) test, this at-home monitoring device removes the guess-work. That said, we do recommend you keep track of the common symptoms of low progesterone, to support any further discussions with your doctor or care team.
Over 20,000+ couples have used Inito’s fertility monitor to conceive. It helps you keep track of hormones, provides real-time values, and builds a concise picture you can present to your doctor.
Created to put you in the driving seat with empowering knowledge of your own hormonal health, Inito’s at-home monitor:
- tracks up to 6 fertile days
- confirms ovulation
- shows your hormone charts
- measures actual hormone levels
- works in just 4 easy steps, connecting to your phone
All designed to help you get pregnant, sooner. With the Inito Fertility Monitor, you can track your fertile days by measuring your estrogen and LH levels, and confirm ovulation by measuring your progesterone (PdG) levels.
Use code FERTILITYHELP15 at checkout for 15% off the Inito Fertility Monitor, exclusively available in the US.