First of all, let's not call it a "phase." Calling what you're going through a phase diminishes what you are going through. What is happening is you are looking at yourself and trying to figure out who you are. That is a good thing!
Questioning your sexual orientation is a very normal thing to do. Gay, lesbian, bisexual and transgender people often have questions. If you are feeling this way today, does it mean you will always feel this way? Maybe, maybe not.
Some people may seem like they’re born knowing they’re gay. But actually, most people in the process of coming out do question their sexuality. Some will eventually come out as gay, lesbian, bisexual or trans, but others will decide that they are straight. Each and every one of these identities is okay, as long as you are comfortable and true to who you are.