Question about marriage

Did any of you who are married ever question the person you are with? I feel like its normal to question the relationship once in a while, but then there are people who say if you doubt it at any point he's not "the one"? I don't want anyone else but I worry that if I question the relationship for a moment I shouldn't be, my feelings always go back to him and I am very happy in my relationship, I just don't know if I've let people get in my head too much.