Menstruation Menstrual Period Calculator and Calendar

First Day Last Period:
Length of Period: Cycle days:
Next Period BeginsEndsFertility BeginsOvulationDue date (If Pregnant)

    When is the first day of the menstrual period cycle?

    The first day of the menstrual cycle is also the first day of your menstrual period and that is the very first day you observe bright red blood. Brown spotting is not considered a menstrual period.

    Your menstrual cycle (the time between the the first day of your menstrual period and the first day of your next menstrual period) and the first day of your menstrual period are the same day, and that day is the first day you see red, the real blood, not just some brown discharge. Brown discharge is not considered a menstrual period.

    However, some women with spotting several days before their menses may or may not have an issue with hormones and the corpus luteum (short corpus luteum phase).

    If you are trying to get pregnant and you have regular spotting before your real period begins, we suggest that in addition to using the ovulation calendar, you also add BBT (basal body temperature) and an ovulation detection kit in order to find out when you get pregnant. If you have a lot of spotting  you might want to talk to your Ob-Gyn and assess your progesterone level shortly after presumed ovulation.

    What happens during a menstrual cycle?

    The menstrual cycle begins with the first day of bleeding of the menstrual bleeding or period, and the menstrual cycle ends the daye before the next menstrual bleeding.
    There are essentially two halfs of the menstrual cycle:

    1. The follicular phase, when the follicle develops inside the ovary
    2. The luteal phase after ovulation when the corpus luteum develops in the ovary in the area from where the egg was ejected.

    In the first half of the menstrual cycle, during the follicular phase the levels of estrogen (the "female hormone") start to rise. Estrogen plays an important role in keeping you healthy, especially by helping you to build strong bones and to help keep them strong as you get older. Estrogen also makes the lining of the uterus (womb) grow and thicken. This lining of the womb is a place that will nourish the embryo if a pregnancy occurs. At the same time the lining of the womb is growing, an egg, or ovum, in one of the ovaries starts to mature. At about day 14 of an average 28-day cycle, the egg leaves the ovary. This is called ovulation. At this point the follicular phase begins.

    The follicular phase begins with ovulation, after the egg has left the ovary. If it gets fertilized, the fertilized egg travels through the fallopian tube to the uterus. Hormone levels rise and help prepare the uterine lining for pregnancy. A woman is most likely to get pregnant from having sex during the 3-4 days before or on the day of ovulation. Women with cycles that are shorter or longer than average may ovulate before or after day 14.

    A woman becomes pregnant if the egg is fertilized by a man's sperm cell and attaches to the uterine wall. If the egg is not fertilized, it will break apart and gets absorbed. Then, hormone levels drop, and the thickened lining of the uterus is shed during the menstrual period or bleeding. 

    Pelvic Pain One Week Before Menstrual Period

    Cyclical pain, pain that's related to the menstrual cycle, in a reproductive age woman, almost always has something to do with hormones and ovulation. Any abdominal or pelvic pain occurring monthly should be examined to see what changes of anatomy and physiology may be responsible for causing the pain.

    Many times the diagnosis of such pain is very difficult unless diagnostic studies are used or exploratory surgery such as laparoscopy is performed to look inside the abdomen. The exact timing of when and how long the pain occurs in relation to a monthly menstrual cycle can often be a clue as to what types of pathology to look for on the imaging studies or surgery.


    What would cause pain occurring 7-10 days before menses each month?

    In the week or two prior to menses a corpus luteum cystic gland forms on one of the ovaries at the site where an egg was released from that ovary. This is a hormonally functional gland that produces progesterone primarily. The gland causes the ovary to become larger and heavier for a while until the cystic area goes away when menses starts.

    The other main pelvic change in the week or two prior to menses is that the veins of the pelvis often swell (dilate) under the influence of progesterone. They can become like varicose veins of the pelvis and sometimes will produce a throbbing pain, but which lasts throughout most of the last week of the cycle.

    Since the pain only lasts for 3 days and it does not start 14 days before menses but rather 7-10 days, the best guess as to cause would be that the pain has to do with the enlarging ovary on the right. One would expect the pain to alternate sides if it were due to a corpus luteum gland because ovulation usually alters one month from one ovary and one month from the other. However we have seen ovulation occur pretty regularly from only one ovary even though there appears to be no disease in the other one.

    Pain occurs when the enlarging ovary "pulls" on any adhesions of the ovary to the surrounding tissue or simply when it stretches the ovarian capsule fairly rapidly. Adhesions cannot be seen on ultrasound or any xrays but if you have your pelvic ultrasound during the 3 days you are having pain, One would expect to see a cystic area (small) on the right ovary if that is where you are having pain.

    Learn How to Calculate Menstrual Cycles Manually

    1. Get a calendar. This can be either a paper calendar or one on your computer, phone, or tablet.
    2. Mark the FIRST day of your LAST period with an "X". This is day #1
    3. Count forward however many days your menstrual cycle normally is before you start. If you don't know, then just count 28 days.
    4. Put your initials or some other identifying mark on the last day. This is when your period should start.

    That's it! If you have never monitored your period before, after several months you'll be able to figure out your actual cycle length and adjust your calculations accordingly.