Yes, this is normal and is a sign of your uterus stretching to accomodate the growing fetus. However, if the pain is accompanied by bleeding, contact your doctor ASAP!
No it is not normal. You consult a gynaecologist soon. If periods start in the middle of
pregnancy the chances are for abortion. So don't be silly take it seriously.
It is normal to have cramps during the very early weeks of pregnancy as hormone levels are changing rapidly and the uterus is getting ready to expand. It should be temporary.
It is very normal and common to have menstrual like cramping during the first five weeks or pregnancy and to feel as if you are going to get your period.