Could I be bisexual? Or lesbian?

this a little detailed... Im in a relationship with a man, I have a 1 yr old daughter and im 6 months pregnant. the thing that worries me is that I may be bisexual because when ever I masturbate I think of women instead of men and when my partner does oral on me I have to think of girls to be able to have an orgasm... But the weird thing is that when we have regular sex I love it, and im so attracted to him. Ive had the chance to kiss a girl but I coildnt do it cus I thought it was gross, but how come when I see two girls doing sexual things besides kissing i get turned on? am I bisexual?