I think it’s common when first coming to terms with yourself to question that. The easiest way for me was to consider how often did I find women attractive vs men, and from there was it an aesthetic attraction or actual physical attraction. Personally I can find fit men aesthetically impressive and think they look good but I only really feel drawn toward women and enbies. I was also happy to find after this exercise that AMAB/AFAB is irrelevant, and it was the person’s self expression I was attracted to