Hi, Courtney! I turned seventeen this February 15th (2018) so it doesn't take much to transport myself into the mindset of my sixteen-year-old self. Maybe some of the other people who responded are about your age too. I must admit I didn't actually check.
As a lot of people have already outlined, the aromantic spectrum and the asexual spectrum are two different spectrums! You can be allosexual (the opposite of asexual) and aromantic at the same time. It sounds like those might be some labels that fit you, if you are looking for labels.
In addition to what others have already posted here, I'd like to tell you: don't worry about being sixteen and it's ok if it is indeed "just" a phase. If you aren't experiencing romantic attraction right now but you do experience it later, it doesn't mean that you weren't really aromantic when you were sixteen. It just means that that label doesn't describe you well anymore. You hurt no-one by using that label now. Even if you did, it isn't your job to play respectability politics and worry that by identifying with this label at a young age and potentially dropping it later, you might reinforce stereotypes about people who identify as aromantic. It is not your responsibility to make people who identify as aromantic worthy of respect from bigoted people. It's their job to educate themselves and to let us educate them if we're feeling up to it. If it turns out to be a "phase" aka a temporary stage in your life, that's OK! Being a teenager is an age for exploring your identity and figuring out what and whom you're into and what you like being called and calling yourself. It's saddening that "phase" has become a dirty word. Having a fluid romantic (or sexual) identity, that is, going through phases, is fine, no matter what age you are. It's always OK to change your labels later if you like and it's OK to be fast and loose with your labels if you want to be!
In ninth grade, I knew one other person who identified as on the aromantic spectrum. They worried that they only identified as aromantic because they were on hormone blockers, and that as soon as they got off hormone blockers, they would start experiencing romantic attraction. It didn't help that their family told them this, or at least insinuated this, a lot. I told them that if that were the case, it was fine. They were hurting no-one by identifying as aromantic in that moment! They weren't getting crushes, so they got to call theirself aromantic! The label is for you to feel better about yourself, not to play respectability politics with. The label is for you, not for other people. Just like there are a lot of mentally ill or neurodivergent people on this server who had to deal with self-doubt and/or invalidation about their identity because of their mental state, they realized that it doesn't matter if that's the "reason" they're on the aromantic spectrum. They get to decide if they identify as on it and they are not obligated to consider how that might impact the image of the aromantic community. The community exists to support each other, not to throw vulnerable members under the bus.
I started identifying with the word aromantic about the time I was turning fifteen. At that time, I had only had at most two experiences that were sort of crushes but not really. After about a year of identifying as gray-aromantic because I felt unsure of one of those experiences, I got a full-on crush on someone. I got to stick with the label I was already using since I was already using gray, but I did move on the spectrum. I was less aromantic than I was before that, and that was OK. No-one was hurt by that. If I start getting lots and lots of crushes, at what is considered the "normal" rate/amount, then I will drop my label as a person on the aromantic spectrum, because it wouldn't fit anymore, and that will be OK. I will still advocate just as strongly against amatonormativy, allonormativity and stereotypes against aromantic people. Maybe even more people would listen to me because I'd have allo-privilege then.
If I used any terms you're unfamiliar with in my post you can almost certainly google them and get a good explanation, or you can search for them on this server, or you can ask me! I'm happy to clarify anything if that would help.
I hope this post is beneficial for you or for other people.