Your hormones go up and then down–a bit of a roller coaster ride. This is part of the reason why many people with periods experience a wide range of symptoms during this time!
Let's dive into it a bit more. If you want to refresh your memory on what happens in the follicular phase, check out this post.
After ovulation, the follicle shell, now called the corpus luteum, produces progesterone.
Progesterone peaks about six to eight days post-ovulation, influenced by luteinizing hormone (LH). This is why progesterone is tested during this part of the menstrual cycle!
Progesterone causes some noticeable changes, like a slight rise in basal body temperature (BBT) and thicker, tackier, and more acidic cervical mucus. This mucus acts as a natural contraceptive, making it harder for sperm to survive and move compared to more fertile mucus.
During the luteal phase, the endometrial lining goes through a process called decidualization, making it more receptive to a potential pregnancy.
While both estrogen and progesterone are needed, progesterone plays a major role. It stabilizes the lining, recruits immune cells, and stimulates blood vessel growth.
If pregnancy occurs, decidualization continues, and the corpus luteum keeps producing progesterone and estrogen, as well as inhibin A to maintain the thick endometrial lining, prevent uterine contractions, and block new follicles from developing.
If there's no pregnancy, then the sac called the corpus luteum breaks down after about ten to twelve days. This means a period will start roughly two weeks after ovulation.
If you ovulate, you should have a period around 2 weeks later. This is a great retrospective tool for gauging ovulation–once you get a period, look back and see if you ovulated 12-14 days ago!
Obviously, there are times when this measurement can be inaccurate, like in cases of luteal phase defect, where the corpus luteum doesn't produce enough progesterone, or the uterus doesn't respond well to it. This can cause fertility issues, premenstrual spotting, recurrent pregnancy loss, and short menstrual cycles.
As the corpus luteum deteriorates in the late luteal phase, it becomes the corpus albicans. The levels of progesterone and estrogen drop, triggering a series of events: follicle recruitment for the next cycle, destabilization of the uterine lining, immunological changes, inflammation, and menstrual bleeding to shed the built-up lining.
In the week leading up to your period, you might experience fluid retention, cravings, mood swings, digestive changes, and fatigue due to hormonal shifts. Mild changes are normal, such as needing more calories (30 to over 200) depending on your metabolism and activity level.
This can lead to increased appetite and cravings or even less exercise tolerance. Make sure to stay hydrated! This is especially important if you're active, as your fluid and electrolyte balance might be affected.
If you experience severe symptoms like extreme mood swings, migraines, or a sense of not being able to cope with life, it's important to seek help.
Everyone experiences hormonal shifts differently. Our brains perceive these changes differently before and after ovulation, and these perceptions can evolve as we age. Our lives, environments, and hormones are interconnected, influenced by childhood experiences, lifestyle, stress, genetics, nutrition, resources, geography, social supports, and more.
Even though the premenstrual phase can be challenging, there are ways to smooth out the ups and downs. You can check out this blog post for guidance.
The Period Literacy Handbook also has some great info on the luteal phase in Chapter 3 and PMS in Chapter 16.
