If youre straight is it possible to turn bi out of no where?

i have always found women pretty but have always seen them as just friends. it has never crossed my mind to date a women. ever. i LOVE men, but as i get older(im 19) im noticing that women sort of turn me on. my very first kiss was a women(my friend). but i also started turning to women as I became bitter with men. i dont trust men very much and i dont see how a man can like me for more than just (thats all theyve ever wanted). ive never had a bf either. are these feelings due to my bitterness with men, or am i really bi?