Blame it on pheromones. Even if you're not conscious of it, they're working.
It has been shown that after some time, women who live in close proximity to each other begin to synchronize their menstrual cycles.
No it shouldn't effect your menstrual cycle as you are not on any medication. However, it is possible for women who closely associate with each other or live together, for their cycles to arrive around the same time.
Menstrual Synchrony
The typical menstrual cycle length is around 28 days long, but everyone is different. Menstrual cycles will not always be the same length, up to a weeks variation from your average cycle is normal.
Yes, they often do.
You were five days later than you predicted - this prediction was based on your average menstrual cycle length, but menstrual cycles change and they will not be exactly the same throughout your entire life. Anything up to a weeks variation from your average menstrual cycle is normal, also things such as ill health or stress can delay your menstrual cycles too.
Your periods aren't determined by the dates on the calendar, they are determined by your menstrual cycles and your cycles will never perfectly sync up with the calendar months. The average menstrual cycle is 28 days which is shorter than a month, cycles can change, and months aren't all the same lengths - there's no reason at all to think your period would always occur on the same day every month.
Women who spend a lot of time together sometimes end up having their menstrual cycles in sync. It simply means that you two are spending a lot of (hopefully happy) time together.
I don't have an answer but I have the same question.
29.5 days. There's a lot of mystical new-agey mumbo-jumbo about it being tied to women's menstrual cycles, but the problem with this theory is that if there were much to it, all women would be on the same cycle and they're not. It's vaguely possible that at one time the menstrual cycle was actually linked with the moon phase, though since there's no evolutionary benefit to it they're not any more.
Women go into labor at any time. After working in an OB/GYN for 2 years, we noticed a pattern of women going into labor anywhere from immediately to 24 hours after a full moon. They do call menstrual cycles "lunar"!
keep male dogs out of contact. and be sure to clean up any blood coming from the dog. make the dog more comfortable. women wants to be as comfortable as possible during their menstrual cycle. do the same for your dog.