Questioning sexuality

Is it normal to question your sexuality? I’m a 17 year old girl, and NEVER have! I’ve always been hella attracted to guys. I’m currently in the relationship with a handsome boy, and it’s been a year and a half. And I woke up one day and questioned myself and it’s tearing me apart :/ if I’m questioning myself, does that mean I’m not straight? I don’t see myself with girls, nor do I want to be with them