Can I get my period when I am pregnant?

Someone asked us:
Q. Can I get my period even though I am pregnant? A friend of a friend didn’t know she was pregnant until she was in her 5th month because apparently her periods kept coming. Are they actually periods or is this just a myth?
A little vaginal bleeding during a pregnancy isn’t unusual — it happens to one in five pregnant women. Some women might mistake it for a period, but it’s not.
Bleeding during a pregnancy can be a sign that something is wrong, so it’s important to contact your nurse or doctor right away if this happens.