Am I bisexual ?

I (28F) have always thought I was straight. For a little context, I was born in a country where being gay is still a huge taboo. I didn't even know what the words gay and bisexual meant until I moved to France at 18 yo.
But since I liked guys anyway, it never really occured to me to question my sexuality.. until now.
Eight months ago, I met a girl at work, and we hit it off really quickly. She's bisexual and has a preference for girls. We became friends, and then roommates. It's been fun living with her. But it's making me question my straightness.. I kind have a crush on her ! I think she's super cute and funny, and I had a sexual dreams about her the other night. Am I bisexual? How come I never had any suspicions or hints of my attraction to girls before now?
Also, what do I do about this crush?