Do I ask out my crush

All right so I really do like my crush. Like thinking of having another Crush feels weird the point is I really like my crush. she's not popular or anything she's average. but I like her anyways. I try to talk to her everyday. but I feel like I come out as annoying recently and that's annoying her and she doesn't really care. She used to smile at the end of our conversations but she hasn't been doing that. maybe because I haven't got a full conversation or something I don't know. My heart is telling me to ask her out. but my Gut is saying no. because School relationships don't really work out and it will make things awkward. And I would ask her out to prom senior year I don't really know. Which one do I choose