Need to give it time, If you feel the same way in a few years, then you're bi, If not, then just a phase
your the only one able to answer that.Just go with what ever feels right to you.
time will tell
My suggestion, is never ask this question. Do not wonder if you are gay straight or bi. Ask "Is this individual attractive". Saying you are gay straight or bi is like saying "The only dessert I like is Cherry pie".
That's kind of like asking does ONE picture of you define you. Don't be worried about labels so much. Time will tell. Just enjoy yourself, and the answer will come to you.
its just a phase.
Maybe, maybe not. You'll see.
bi but it's kool good luck