Luteal Phase

What is the luteal phase of the menstrual cycle?

The luteal phase of your menstrual cycle occurs right after ovulation (when your ovary releases an egg). It lasts about 14 days and ends when you get your menstrual period. The luteal phase is one of four phases of the menstrual cycle. The main purpose of the luteal phase is to prepare your uterus for a possible pregnancy.

During this phase of your cycle, an egg travels from your ovary through your fallopian tube and to your uterus. If sperm fertilizes that egg, the fertilized egg implants into your uterine lining and pregnancy occurs. If the egg isn’t fertilized or doesn’t implant (pregnancy doesn’t occur), you’ll get your period. Your luteal phase is over when you get your period.

Phases of the menstrual cycle

Each phase of your menstrual cycle plays an important role in reproduction:

• Menstruation: This is when your uterine lining (endometrium) sheds through your vagina. It’s also called your period. Day one of your period is the first day that any vaginal bleeding occurs.
• Follicular phase: This is the phase where your ovaries prepare eggs for ovulation. Eggs develop in your ovaries inside follicles. One follicle develops into the most dominant follicle and releases an egg that cycle.
• Ovulation: Your ovary releases the egg that developed in the follicular phase.
• Luteal phase: The luteal phase starts when an egg begins its journey to your uterus. It ends when you get your period (menstruation).

The cycle repeats until menopause unless pregnancy or other health conditions prevent it from reoccurring.

What happens during the luteal phase?

The luteal phase begins after you ovulate. The dominant follicle that releases an egg at ovulation changes into a structure called the corpus luteum. The corpus luteum produces progesterone, along with some estrogen. Progesterone levels increase in the luteal phase, which help thicken the lining of your uterus. The increase in hormones:

• Prepares your uterine lining for pregnancy by making it thicker. The thick lining is the ideal environment for a fertilized egg to implant (attach) and a pregnancy to grow.
• Causes your cervical mucus to thicken into a paste. The thickened mucus helps prevent bacteria from getting inside your uterus.

If you don’t get pregnant that cycle, the corpus luteum dissolves and hormone levels decline. You shed your uterine lining during your menstrual period.

Is the luteal phase always 14 days?

The average menstrual cycle is 28 days. The average length of the luteal phase is between 12 and 14 days. However, like your menstrual cycle, there can be variations to the luteal phase. A luteal phase that lasts 10 to 17 days is considered normal.

Short luteal phase

A luteal phase that lasts less than 10 days is a short luteal phase. This means you get your period within 10 days of ovulation. A short luteal phase doesn’t allow your uterine lining to grow and thicken enough to support an embryo. As a result, people with a short luteal phase may struggle to get pregnant.

A short luteal phase can also be a sign of a luteal phase defect (LPD). A luteal phase defect is when your uterine lining doesn’t grow or thicken enough to support a pregnancy. LPD can cause infertility or miscarriage.

Long luteal phase

A long luteal phase is the opposite of a short luteal phase. It means your period comes 18 days or later after ovulation. People with a long luteal phase may have a hormonal imbalance like PCOS (polycystic ovary syndrome). If you don’t get your period within 14 days of ovulation, taking a pregnancy test might be a good idea.

How long does a luteal phase need to be to get pregnant?

If your luteal phase is too short (less than 10 days from ovulation), it may be hard to get pregnant because your uterine lining doesn’t have enough time to thicken to support a pregnancy. However, everyone’s body is different, and just because your luteal phase is shorter than average doesn’t mean you can’t get pregnant. It’s always best to consult with a healthcare provider if you’re trying to get pregnant.

How do I know if I am in the luteal phase?

There are some ways you may be able to tell you’re in the luteal phase. Not everyone will notice symptoms.

Basal body temperature

Keeping track of your cycle using basal body temperature, or your body’s resting temperature, is one way to know if you’re in your luteal phase. If you take your temperature immediately after waking, you’ll notice a slight increase in your body temperature after ovulation. The shift can be as little as 0.4 degrees Fahrenheit (0.22 degrees Celsius).

Vaginal discharge

Another way to tell if you’re in the luteal phase is to look at your vaginal discharge. Your cervical mucus changes throughout your menstrual cycle. During ovulation, your discharge is wet and slippery like egg whites. It gets thick, dry and paste-like in the luteal phase.

Symptoms of the luteal phase

Symptoms of the luteal phase resemble those that happen during PMS (premenstrual syndrome).

Some signs that you’re in the luteal phase of your cycle include:

• Mood changes.
• Tender breasts.
• Bloating.
• Breaking out or acne.
• Changes in your appetite.

Can you get pregnant in the luteal phase of your menstrual cycle?

Conception, or the process of sperm and egg meeting, occurs in the luteal phase of your menstrual cycle.

It’s important to note that conceiving and being fertile aren’t the same. While conception happens during the luteal phase, your best chances to get pregnant (the most fertile days of your cycle) occur in the follicular phase. If you wait until AFTER ovulation to try to get pregnant, you only have 12 to 24 hours for conception to occur. You’re most likely to get pregnant if you have sex in the five days BEFORE ovulation, which is during the follicular phase. Using an ovulation calendar may help you figure out when you ovulate.

A note from Cleveland Clinic

Knowing the phases of your menstrual cycle can be extremely helpful, especially if you’re trying to get pregnant. Talk to a pregnancy care provider or fertility specialist if you’re concerned about the length of your menstrual cycle or think you aren’t ovulating. If pregnancy isn’t your goal, it’s still helpful to know your body and be aware of how problems with your cycle can affect your health.