It's most likely a phase. Yes, it is possible to experiment with guys and girls and then decide later who you are truly attracted to.

For all of high school I fluctuated between bisexual and lesbian, but now that I am in college I realize I could never see myself having sex with women and prefer men, so now I find no attraction in women, though I dated, made out with, and found attraction to women. I don't see myself as neither gay nor straight, so I have no label currently.

Don't worry about labels so much but focus on who you want, what you like, and what makes you feel good.