Is it possible to be slightly biual ?

Ohkay, right now I'm dating a guy and I love him so much and am very attracted him to him ( emotionally ually physically etc ) but for the last year or more I've found myself looking at girls more often, like there bodies and features etc. I've even imagined myself ually with girls. Now idk if this is just curiousity ( I'm only 16 ) or could I possibly be or just slightly ? When I wad younger (13 ish) obviously it's normal to be interested in more mature things and our bodies and others but if anyone who has gone through this can give me some insight that'd be great thanks !! :)