Any prescribed safe time has exceptions. The safest way is either the male uses condoms or the female to use pregnancy avoiding tablets or other means. See links below for more information.
Im not sure of the exact percentage but i would say its in the 90's
There can be several causes for excessive menstruation. Some of those causes are hormone imbalances, fibroids, ectopic pregnancy, and endometriosis. You should consult with your physician to determine the exact cause of prolonged periods.
The exact same way a adult pregnancy happens!
I believe your question is along the lines of a fertilized egg not making it to the uterus. If so, that is often called a tubal pregnancy. Look up "ectopic" pregnancies and you'll find lots of info. HTH
Having these mood swings is the exact sign of pregnancy.
sometimes it is because of harmonical disorders....But many times,it means that the girl is pregnant...
The doctor will use a combination of an internal and external exam to feel the uterus to see how far along in a pregnancy a woman might be, but generally an ultrasound determines the exact date. The uterus actually moves and changes during the pregnancy, making it easy to feel the changes.
Your menstrual cycle is the entire reproductive cycle including ovulation and menstruation - I think you mean menstruation of five days, not menstrual cycle. Menstruation will vary from one cycle to the next, the explanation is no more complex then that your body is not a machine so it will never have the exact same cycle every single time.
Don't risk it, see a doctor.. Pregnancy tests aren't always exact.
You will need to go to a doctor and get tested to find out the exact cause of your pregnancy issue.
Cloning
You would seem to have had sex at the peak of the ovulation cycle, so the chances would seem good. However, pregnancy isn't an exact science; conception relies on many variables in both the woman's body and the man's sperm. Wait for your next period. If it doesn't come, have a pregnancy test. Either way, you may wish to speak to your local sexual health or family planning practitioner for confidential advice on conception.