Sexual confusion

I'm not sure if I'm bisexual. I was married, so I considered myself straight. Then I was with a woman for a few years and considered myself a lesbian. Since then, I've been with a man and consider myself straight. I feel that being bisexual means being equally attracted to men and women at the same time. When I was with a woman, I was only with her. Now, being with a man, I think of myself as being straight again. I don't know....