It is perhaps slightly shorter than many but is it not unusual nor can it be called abnormal.
yes
You've actually already answered your question. If you have a 25 day cycle then your period will start on day 1 and occur every 25 days!
NO this is not normal.... See a bloody doctor ASAP!!
On day 10 or 11 usually
During a 25-26 day cycle ovulation would likely occur around day 11 of the cycle - however unless using something like fertility awareness method you would not be able to aqccurately determine when you ovulate or when you're fertile.
Depends...per WebMD (http://women.webmd.com/tc/normal-menstrual-cycle-normal-menstrual-cycle), "The menstrual cycle is measured from the first day of menstrual bleeding, Day 1, up to Day 1 of your next menstrual bleeding. Although 28 days is often cited as the "regular" cycle length, only 15% of women actually have such a cycle." * A teen's cycles tend to be long (up to 45 days), growing shorter over several years. * Between ages 25 and 35, most women's cycles are regular, generally lasting 21 to 35 days. * Around ages 40 to 42, cycles tend to be the shortest and most regular. This is followed by 8 to 10 years of longer, less predictable cycles until menopause.
Nothing at all, it's normal. 28 days is the average menstrual cycle length - everyone is different so not everyone will have a 28 day cycle, also it's normal for cycles to change over time and for there to be a few days variation from one cycle to the next. If you go over 28 days then that simply means that your cycle is longer than the average menstrual cycle. Rather than expecting your periods every 28 days you should determine your own average menstrual cycle length. One menstrual cycle is the number of days from the first day of your period up until your next period, you add all these days together over your last 6 cycles and then devide by 6 to get an average. There are various apps for your phone or web sites that figure out your average menstrual cycle length for you. Take my cycles for example; July 25 (35 day cycle) June 20 (32 day cycle) May 19 (32 day cycle) April 17 (27 day cycle) March 21 (31 day cycle) February 18 (26 day cycle) So my average menstrual cycle is 33 days - as long as my periods fall within 26 to 40 days they are still regular. So you see my cycle is longer than 28 days, and there can be a little variation from one cycle to the next, this is totally normal and healthy.
This is just a result of being a human being, you are not a robot and thus your cycles will never be exactly the same. Anything up to a weeks variation from your average cycle is normal.
Sometimes periods get irregular or develop a strange cycle. You should see your doctor because it can develop into anemia. Docs can prescribe meds to get your period back to a 25 day to 32 day cycle instead of a 14-16 day cycle.
I've read that ovulation typically occurs 14 days before menstruation begins, so if you are on a 25 day cycle, then ovulation is around day 11 or 12.There are methods of determining when you ovulate - a web search should produce lots of results.
The Cycle - 2012 2013-03-25 was released on: USA: 25 March 2013
The Cycle - 2012 2013-02-25 was released on: USA: 25 February 2013