It is not possible to have a period during pregnancy
When a woman has her period the lining of her uterus is sloughing off. That lining built up during her cycle so the fertilized egg would have a good place to implant, after the cycle is over and the egg is no longer alive and no egg implanted a woman will get her period. The next month she will do the same thing again, grow a lining in her uterus, wait to ovulate, wait for the egg to get fertilized and then slough off again if no fertilized egg implants.
When a woman gets pregnant the lining of her uterus does not slough off. The lining is there to feed and nourish the fertilized egg/embryo until the placenta is about to form.
Some women do experience bleeding during their pregnancy. The bleed is not normal and could be caused by a variety of things. If you have any bleeding during your pregnancy you should contact your doctor right away. Some bleeding during pregnancy is harmless but some bleeding can indicate a serious problem. Some women will have bleeding during pregnancy and mistake it for their period but it is not really their period. It is impossible to get your period while you are pregnant.