Q: Gay Or Not Gay (Worrying)

Hey, it started around 4 days ago when I just couldn't get hard anymore on woman. My only thoughts went to gay porn and I just got hard on that. Now here is that I don't have any feelings at all for boys but it's just the gay porn that interests me. Is this normal? And will I ever be able to do it with woman again? And is this a normal thing in puberty (My Age: 13).