This sounds stupid

Hey guys, so I have a question... I know you can’t have a period while pregnant. However, I saw this video of a girl saying she had her period THE ENTIRE TIME she was pregnant... so my question is how is that possible ? I’ve taken 2 pregnancy tests, both came out negative. And then I got my period twice since then. Last one just ended April 15th. But now I’m paranoid like wtf? Someone explain please