Help ami straight or bi?

Sooo Ive benn thinking for like 2 yes tht I'm gay/bi �but it's confusing when I was in pe I use to hide in the back of the lockeroom so I would stop starring at guys chest and bodys and stuff it's not tht I got an erection because I haven't looked long enough to see if I get one, but any ways I do get off on gay porn but not as much as regular porn but �somtimes at school when I see girls �they all of a sudden look weird or like I'm not attracted to any of them but then maybe 2 or 3 days after Iam again I'm soooooooo confused any advise will help thx