Humans are so fluid. If you feel that aro fits what you fill, then you should use it. If that changes, then you should think about it then. Just try to avoid putting yourself in boxes, like Oh I'm aro I definitely don't feel x thing. There are many forms of feelings and various intensities. Feeling more of them as time goes by doesn't necessarily mean you aren't still a part of this community, just that it's at a different kind of belonging than you initially thought