While it is possible to have period-type bleeding while pregnant it is not the norm. Most women do not have bleeding while pregnant.
A period by definition would mean you are not pregnant. It is the sloughing off of the uterine lining. A fertilized embryo implants into that lining so if you were to have a true period that lining would bleed out.
BUT you can have bleeding during pregnancy; it just is not a period. The bleeding is typically caused by a hematoma, a placental issue, a cervical issue, old blood that has gotten trapped, etc.
It's different for each woman and each pregnancy. One of my friends experienced no bleeding during her pregnancy, and another had period-like bleeding for 3 mos. into her pregnancy. It's a case by case basis really.
Some women do have period like bleeding in pregnancy but this rare. I had three period type months of bleeding for the first three months of my first pregnancy but I did have symptoms of pregnancy and the bleeding was different from my normal period x
You stop having them until after the baby is born.