Me and my best friend have been getting our?

Question

period on the same day for the past three years.

i am 15 and she is 14.

we have been friends sence we were about two.

we ever got our period at the same day when i was 12 and she was 11.

is this normal?

we end, and being on the same day.

Answer 1

It is normal for women who stay around each others a lot to have their periods at the same time. That is caused by pheromones, hormones we produce that travel in the air but that we can't smell, which cause our cycle to sort of go in sync.

Usually easily noticeable in girl dormitories or in families with mother and daughters.

Answer 2

Totally. See, when you're around someone for that long, your hormones match your best friend's hormones. So you end up getting your period on the same day. It happens sometimes with sisters also.

Answer 3

its called syncronizing (sorry i spelled it wrong)

Answer 4

thats actually completely normal. thats the case with me and my sisters. its just because youve been together for so long your bodies become synchronized. completley normal

Answer 5

It is coincidental. I am a guy and I know this. Sad.

Answer 6

women who spend lots of time together tend to do something called "tribing", where the women all seem to synchronize their periods around the same time. It happens in offices, and anywhere women are together alot.  It's nature's way of ensuring reproduction.

Answer 7

Yes, it's normal for our bodies to be in sync with one another.  Me and my 3 sisters are back to back with our periods LOL.

Answer 8

mhmm. its your pheromones. if you hang out with someone a lot then your periods sinc up. my step mom and i are on the same days when im home for a long period of time.... and if i hang out with a group of friends a lot then we all sinc up too. totally normal.

and im talking months of being around each other, like you and your friend... not like a couple days. :)

Answer 9

now that is what i call strange!>x

Answer 10

maybe it's just a coincidence.  

Answer 11

Menstrual Synchrony

Julia Wise

Generations of women have noticed it: you and your sister, or your roommate, or lover, or mom, get your periods at the same time. It doesn't always happen, but it catches the attention when it does. Female rats living in the same air space ovulate at the same time. Menstruation in monkeys synchronizes with the full moon (7). So is it all in our heads, or is the same pattern present in humans?

The clearest argument against the existence of menstrual synchrony is that since the length of the menstrual cycle varies from person to person (2), two women with different cycle lengths will never synchronize. They may menstruate at the same time, but the next month they will be a little different, the next month more different, and so on. By this argument, synchrony is simply a myth.

I cannot believe this argument, since it assumes that menstruation can be graphed and analyzed like a sine wave. Human bodies rarely adhere to perfectly timed schedules. Many women have irregular periods, and the regularity of the menstrual cycle changes at different stages of life (3). So if a woman with a cycle of 25 days and another with cycle of 28 days live together, they might both shift to a cycle of 26 or 27 days. In this way, synchronization would still be quite possible.

So if this phenomenon does exist, what explanation can there be for it? One theory is that lunar cycles may have some connection to the pattern. At first this makes some sense, since both cycles happen about thirteen times each year. A study on the Dogon people of Mali found that although they had no electricity and spent most nights outdoors, thus being as likely as anyone to be affected by the light of the moon, menstrual cycles among the Dogon did not match up to any lunar phase. Another theory

was that synchronization might be due to the same factor that causes pendulum clocks near each other to tick at the same time. This was later shown to be purely mechanical, though, with the swinging of the heaviest pendulum merely rocking the shelf a little and throwing off the beat of other clocks (1).

The most likely theory is some kind of hormone change. Women's menstrual cycles respond to contact with men, becoming shorter and more regular. So rather than a mechanical synchronization, like pendulum clocks, the cause is more likely chemical. In 1971, Martha McClintock published a study about the 135 women in her dorm at Wellesley College. She found that the synchronization of menstruation between roommates and close friends did increase after the women began living together. McClintock's explanation was pheromones. She co-authored a followup experiment, exposing women to chemical compounds from the armpits of other women. She concluded that this did alter menstruation (4).

There are a number of problems dealing with the statistics of this and other experiments, though. The data can be interpreted to either support or negate McClintock's conclusion, depending on how it is analyzed (4).

Why synchronize? One possible benefit of simultaneous ovulation for the whole population is simultaneous birthing. When female rats give birth at the same time, their pups are significantly healthier and more likely to survive. Certain times of the year may be better for births, as when lambs are born in spring rather than fall. So synchrony may have developed because it is helpful in raising healthy young (6).

The research I have done has increased rather than answering my list of questions. Is the math used in these studies wrong? Most articles I found denouncing the theory were written by men; most supporting it (or even denouncing it but wishing it were true) were by women. So is this just something women want to believe because it would be cool and bring us closer together? Also, according to McClintock, some women responded strongly to other women's pheromones, while others did not respond at all (6). Does this mean that it is not strictly group behavior but leader/follower behavior,

with some women's cycles setting the trend for the others? If so, does this chemical leadership correlate to any kind of social behaviors, like alpha females among wolves? My conclusion can only be that despite all those s*x-ed videos from seventh grade, menstruation is still awfully confusing.

References

1) "Blood, Bread, and 'Menstrual Mind'?", dealing with Judy Grahn's book on menstruation

2) "Convergence and Divergence of Menstrual Rythms", analyzing the math used on Martha McClintock's study

3) "Menstrual Cycle Length as Function of Age"

4) "Do the Menstrual Cycles of Women Living Together Tend to Synchronize?"

6) "Menstrual Synchrony", an interview with Martha McClintock

7) "Converging Menstrual Cycles"

Answer 12

Totally! I lived with my friend for a couple years and we were on the exact same schedule for most of it

Answer 13

When women are around each other a lot it's very common to have your period around the same time. I noticed it when I lived with my mom and sister, and also with my coworkers.  

Answer 14

it's just a coincidence nothing to worry about:)

one of you either missed a few days or had it for longer than the other, and ended up on the same date. it doesn't matter that she is a year younger, it's pretty much the same. sooner or later one person will have an extra day or two of thiers and it won't be the same.

thats really cool though!

Answer 15

for some reason, women that spend a lot of time together eventually end up on almost the same cycle.  Every person I've worked with has somehow ended up starting around the same time as me ...strange how our bodies work !

Answer 16

yeah i get my period a lot on the same day as my friends!