Possible to get pregnant and still have AF?

Is it? I see a lot of posts in this group about that and it seems to me that not everyone is the same. How many of you have gotten pregnant and still got AF?

My mom told me a story about how her biological mother (she was adopted at 6 weeks old, and reconnected with her bio mom 30 years later) had her period for 6 months. And didn’t realize she was pregnant. As it turns out, the same thing happened to my bio grandmas, grandma. Is it possible? I didn’t realize it was, but it could explain some things in our lives.