Yes
ofcourse you should not.you're not doing it right?
Any medical treatment can cause stress on the body, resulting in a late period or completely skipping your period
Exercising can be a cause for your period to be late if you exercise daily.
Pregnancy or stress.
When you haven't had a. Period for a while
Yes, it is possible for your period to be late or stop completely from any hormonal birth control.
Yes, pregnancy is possible even with ligated tubes.
Your period should not be delayed more than a few days, but it is not unheard of either. You should be examined by your doctor, just in case though.
Not impossible, but very unlikely. If you're worried, get tested.
Old blood, which is normal and very common.
yes