Disclaimer: I'm not a medical professional and what I share on this site are my own personal experiences along with scientific research and findings that I cite at the bottom of each article. Please talk to your doctor for diagnosis and treatment.
It might be a little intimate, but I always know I'm beginning my luteal phase when my boobs start to hurt.
Others know they're in the back half of their menstrual cycle when tears start to well up in their eyes for no reason at all.
For others still, it's the cravings or the insomnia that trigger that intuition - "My period is coming soon."
But, then there are those cycles that just feel extra crazy. I've had a few in the past year where I started freaking out, wondering "Why am I nauseated every day?" and "Okay, I know my boobs are supposed to hurt, but they've never hurt like this before." and "Wait...isn't acid reflux a pregnancy symptom?"
All of a sudden, I'm consulting Dr. Google, and she's telling me that my symptoms line up perfectly with the early stages of pregnancy. And before you know it, I've convinced myself to pee on a stick.
If this experience sounds anything like you, you're definitely not alone. It can be confusing to feel different hormonal luteal phase symptoms each cycle and not wonder, "What if..."
To put your mind at ease, I want to remind you of the science.
During the post-ovulatory, back half of your cycle - the luteal phase - the follicle that once surrounded your ova re-seals itself into an in-tact corpus luteum. This corpus luteum's entire purpose is to get the uterus ready for potential implantation. To do that, the corpus luteum secretes high levels of progesterone to build up the endometrial lining. This essentially means whether or not there's a fertilized egg coming down the fallopian tube to the uterus, the corpus luteum is making the uterus as cozy as possible. It's the hormonal version of setting out milk and cookies for Santa and the just hoping he's on his way down the chimney. You set out the milk and cookies either way and the rest just happens.
Progesterone is so essential to a fertilized egg's implantation and survival. If a fertilized egg successfully does implant into the endometrial lining of the uterus, the corpus luteum is sustained by the hCG (human chorionic gonadotrophin) and continues producing high levels of progesterone until the placenta is established.
If there's no fertilized egg, there's no hCG to sustain the corpus luteum and eventually, that supply of progesterone will run out.
What this means that, whether you're pregnant or not, you'll experience that same progesterone spike for several days after ovulation. So, if you've just ovulated and you're experiencing all kinds of weird symptoms, it's likely that they're typical luteal phase progesterone symptoms and there's no way to distinguish whether you're pregnant or not. Timing of progesterone surge symptoms really is the main differentiator between pregnant and non-pregnant people, since pregnant people will continue to see their progesterone levels rise 18+ days after ovulation, while non-pregnant people will experience a steady decline in progesterone when no implantation occurs. More on that in a minute.
For now, let's talk about just what the progesterone-related luteal phase symptoms are. They include:
Acid reflux / heartburn
Anxiety
Breast soreness
Breast enlargement
Belly bloating
Constipation
Cramps
Depression
Fatigue
Headaches
Higher basal (waking) body temperature
Insomnia
Increased appetite and hunger
Increased emotional intensity
Increased sense of smell / taste
Joint or muscle pain
Lower sex drive
Mood changes
Nausea
Strange dreams
Broad array, right?
To make things a bit more concrete, one secondary key progesterone-based differentiator between non-pregnant and pregnant people that have just experienced implantation is a steady increase is severity of symptoms 7-9 days post-ovulation. This increasing rather than decreasing intensity in luteal phase symptoms can indicate that a steady stream of hCG from the newly implanted blastocyst is producing a steady, rising stream of progesterone. Remember that if no implantation occurs, that corpus luteum will release less progesterone towards the end of its life (of about 14 days), so symptoms should lessen when someone is closer to menstruation, not worsen.
I know it's tough, but, if you're wondering whether your symptoms are typical for the luteal phase or more indicative of pending pregnancy, consider timing and intensity to make a more educated guess.
Regardless of whether you're pregnant or not, the rapid increase and decrease in both progesterone and estrogen during the post-ovulatory phase of your cycle is dramatic and appears linked to changes in dopamine and seratonin production - which, in its own right might explain some of the anxiety you feel about these symtpoms! Meta, huh?
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