My mom bleed for the first 6 months when she was pregnant with me.
Yes, trying is right, you can't have a period while pregnant because your uterine lining sheds to release an unfertilized egg when you're menstruating, when you're pregnant, your egg becomes fertilized, therefore you don't shed it or it will cause a miscarriage, you can have pregnancy related bleeding, and it may be around the time of a normal period, but it's not a true period.
Its not a true period...there are other things that cause bleeding in early pregnancy a uti, infection, sex, hemmorage, low lying placenta to name a few. It is impossible to have a real period during pregnancy because a period is when you shed ur uterine lining.