I'm not sure how much you know about asexuality, so please do forgive me if I happen to repeat something you already know.

First off, sexual attraction does not equal romantic attraction or sexual desire. An asexual can feel a perfectly healthy romantic individual without feeling any sexual attraction towards another person. Therefore, yes, it is possible you could be asexual even if you have had crushes.

People often tend to confuse the boundaries of being in a romantic relationship and a sexual relationship as they often come together as one package. Asexuality can separate the two to a point where you can still retain a preference/non-preference towards a certain gender. For example, I'm asexual and bi-romantic, meaning I feel romantic feelings towards both genders but do not feel sexual attraction. Another person I know feels neither romantic or sexual attraction to anyone at all, and she identifies as an aromantic asexual (aromantic being attracted to no one).

If I confused you in any way above, I do apologise. Asexuality can be a rather complex subject, but there is a rather marvellous website called AVEN (Asexuality Visibility and Education Network) which will be able to cater to any complex questions you have. Google it. They have a wonderful Wiki and Forums which are pretty welcome to anyone of any sexuality/gender/life-style. Even if you decide that you're not asexual, it still makes interesting reading material. There's also what the AVEN community likes to call a 'Grey-A' version of asexuality, for people who aren't quite sure or don't feel as if they fit in anything else, or have doubts as you do.

If you do have any questions which can't be answered there, or just don't feel like checking it out, do feel free to ask me anything else. I'm pretty clued up on the subject as I went through my own questioning time as well.

And remember, only you can decide if you are or not. Even I have doubts sometimes; maybe everyone else does too. Nobody can tell you who you are, and don't change yourself to fit the definition. The defintion should fit you.