No authority is in a position to tell you whether you are homosexual, gay, lesbian or bisexual. Only the person who is experiencing such an attraction is in a position to make this decision to label oneself.
Different lesbian, gay, and bisexual people have very different experiences regarding their sexual orientation. Some people know that they are lesbian, gay, or bisexual for a long time before they actually pursue relationships with other people. Others engage in sexual activity (with same-sex and/or othersex partners) before assigning a clear label to their sexual orientation.
Prejudice and discrimination make it difficult for many people to come to terms with their sexual orientation and identities, so claiming a lesbian, gay, or bisexual identity can often be a slow and painful process.