Wondering what happens in your body from one period to the next? You know that fluctuating hormones are responsible for mood swings and physical changes, like those pesky PMS symptoms, but what’s really going on?

To better understand these changes, it helps to know that your period is just one part of your menstrual cycle, which involves a complex sequence of events that prepare your body for the possibility of pregnancy each month. Your cycle starts on the first day of your period and lasts until the day before the next one. On average, a cycle lasts 28 days, though anywhere between 21 and 35 days is considered normal.

Read on for a refresher of what occurs at each stage of your cycle and how you can leverage these fluctuations to improve your relationships, work performance, mental health, and love life. (Note: the timeframes described below correspond to an average 28-day cycle).

1. The menstrual phase (days 1 – 5)
The play-by-play: On Day 1 of your cycle, progesterone and estrogen levels are at their lowest. These plunging hormone levels cause your uterus to shed its lining of soft tissue and blood vessels, resulting in your period.

What you may be feeling: Moody, tired, and unmotivated. You may be feeling cramps, which are the muscles of your uterus contracting to push the blood out of your vagina.

How to make the most of it: Use this time to focus on yourself and relax, perhaps with a hot bath or a gentle yoga class. Remember that you’ll be feeling more energized and motivated in a matter of days.

2. The follicular phase (days 6 – 13)
The play-by-play: As a woman’s period starts, her endocrine system springs into action. First, the pituitary gland releases Follicle Stimulating Hormone (FSH) which causes each of the ovaries to prepare about 15-20 mature eggs. (Fun fact: females are born with about one to two million immature eggs, each in its own shell — or “follicle” — in her ovaries.) Around day 7, the fastest-growing egg emerges as “dominant,” while the others begin to disintegrate. The dominant follicle begins to produce estrogen (days 6 to 12), which “tells” the uterine lining to get thick with blood vessels to make a soft landing pad for a potential fertilized egg, or embryo.

What you may be feeling: As your period ends, your hormone levels are at their lowest, translating into tiredness and low libido. But, as estrogen levels rise (about a week into your cycle), you should be back on your A-game. Estrogen stimulates the release of endorphins (“feel good” hormones) and suppresses the stress hormones cortisol and adrenaline. As a result, the brain fog and moodiness that you may feel before and during your period should dissipate and you’ll be more happy, alert, energetic, and motivated.

How to make the most of it: The week after your period is a good time to give a work presentation, do something outside of your comfort zone, or take a vacation, as you’ll be feeling more optimistic and adventurous.

3. Ovulation (day 14)
The play-by-play: The estrogen secreted by the dominant follicle ultimately triggers the pituitary gland to release Luteinizing Hormone (LH). The surge in LH causes the egg to burst out of the follicle (day 14) and through the ovarian wall — this is the moment of ovulation. The egg drops into the pelvic cavity, where it will be swept into the fallopian tubes and await fertilization. The egg is viable and in the business of fertilization for just 12 to 24 hours after ovulation — after that point, it begins to disintegrate.

What you may be feeling: The high levels of estrogen leading up to and during ovulation helps to increase your libido, and you’ll be feeling more sexy and attractive (yay!). On the down side: Some women may feel pain near their abdomen (which may actually result from the bursting of the follicle), experience acne breakouts, or find increased discharge on their underwear, which is the mucus produced by the cervix (the lower part of the uterus) to capture any sperm and help it to move towards the egg. Hopefully, these symptoms won’t put too much of a damper on your sexy mood.

How to make the most of it: This is a great time to have sex and to experiment in the bedroom, as orgasms will be more intense and easier to reach. However, make sure to use protection if you’re not trying to conceive, this is your most fertile day of your cycle.

4. The Luteal Phase (day 15 – 28)
The play-by-play: Once it releases its egg, the empty follicle develops into a new structure called the corpus luteum. The corpus luteum secretes progesterone, which (like estrogen) thickens the uterine lining and prepares it for the possible implantation of an embryo. After 3 to 4 days in the fallopian tube, the egg moves into the uterus. If the egg was fertilized within 24 hours of ovulation it will implant into the endometrium (uterus lining). On day 26, the corpus luteum will stop secreting progesterone and the lining of the uterus subsequently breaks down and sheds, beginning the next menstrual period.

What you may be feeling: The luteal phase is typically when women experience PMS symptoms, a result of surging progesterone levels. Increased progesterone relaxes the smooth muscle of the uterus, gallbladder, sphincter and intestines, which can lead to bloating. Progesterone is also used to make cortisol — the “stress hormone” — so you may feel more irritable, depressed, and anxious. Finally, depleted serotonin levels (due to higher cortisol) can lead you to crave carbs and sugar.

How to make the most of it: There are plenty of natural remedies that can help you feel better — both mentally and physically. And, don’t forget: you’ll be onto the “happy” follicular phase soon enough.

Angelika Schlanger, PhD, is a Yale-trained-researcher, Health Coach, blogger, food-system reformer, and mom to three healthy eaters (well, sometimes). She helps institutions, individuals, and families create a balanced wellness program that is tailored to their individual needs. Angelika enjoys concocting healthier versions of classic recipes, growing her own organic veggies, and taking long naps on the beach. Read her articles and tips at homehealthlove.com and follow her on Twitter @homehealthlove.