It is possible, but not the only explanation. She could have irregular periods, or maybe she started her Birth Control just in time. The only way to know for sure at this point is to take a pregnancy test. Do keep in mind that some girls have periods while pregnant.
Yes. There are lots of other things that cause it such as: Stress Illness Upset Travel/moving house
yes some women have only one or two periods a year.
No test is 100% accurate.
Yes
If you miss your period and have had sex that month
Only if you're pregnant
If pregnancy may be in periods
Most women miss there first months period after becoming pregnant. Some have their period throughout pregnancy.
Not pregnant, but get a professional opinion about the reasons for missed periods.
A women is supposed to have only one period every month, so if she has two in a month which is rare the chances are that she may not have a period the following month.
Sometimes a woman's period is irregular. They could have their period one month, skip the next, then get it again. This happens more when women are just getting their period (more in teenage years)
Yes these are signs of pregnancy.
if you bleed when you are pregnant it doesn't necessarily mean its your period or you have had a miss carriage. a lot of women bleed during pregnancy so you will still be pregnant if it doesn't hurt x
you count how far along you are by the first day of your last period. So by the time you miss your period you are technically considered 2 weeks pregnant.