If you are putting NuvaRing in for the first time, you have to put it in between the 2nd and the 5th day of your period. Then you 'wear' it for 3 weeks exactly (as in same time in the day), take it out and let 7 days (again, on the hours exactly 7 days) pass before you put in a new one. When you use the first time, you are not protected for the first week the ring is in.
no rats have an estrous cycle, not a mestrual cycle.
Around 7 days
When your ovulating.
the uterine lining builds-up during the proliferate phase of the menstrual cycle. Everyone's menstrual cycles are different, but during a 28 day cycle this phase would be around days 16-28.
You can stop NuvaRing at any time, including mid-cycle. You may have a little less irregular bleeding after stopping it if you stop at the end of the three-week cycle.
Around 7 days
If you used NuvaRing correctly last cycle, you don't need to use a backup method when inserting the new NuvaRing. If it's been more than seven days since you used NuvaRing, you need to use a backup until you've used the ring correctly for seven days.
Extremely low, but unless you're abstinent there is always a risk. Aside from that, sex during the mestrual cycle can cause infections, so be careful.
Just by checking the nuvaring site: [url=http://www.nuvaring.com/Consumer/aboutNuvaRing/possibleSideEffects/index.asp[/url] you get the answer. "Irregular vaginal bleeding or spotting Changes in menstrual cycle" So...yes, it is possible.
usually a cycle but can be 4 months
If you have irregular bleeding or spotting in the first three cycles of NuvaRing, it is likely to improve before the third cycle is done. Brown discharge during the ring free week is common (instead of red) and will stop before or just after the next ring is inserted.
If you haven't had a menstrual cycle for that long you're pregnant or there's something wrong with your health. Either way you need to see a doctor.