Does finding women attractive make me bisexual?

Hi, I'm a 21 year old girl and I haven't lost my virginity yet. I've had very few boyfriends over the years but have only been REALLLY attracted to very few men in my life and they tend to be older men with a few exceptions. But my question is, I find many women attractive. I don't necessarily get turned on by them but sometimes when I see a picture of a really pretty woman I get that tingly feeling in the pit of my stomach but it doesn't last for very long (mostly older, someone who can comfort). I remember feeling my stomach flip flop when I was around my male track coach in high school (who is one of the older men I was attracted to) but I don't know if it was the same. I don't know, I guess I just feel self conscious while noticing how attractive women are. I've never wanted to have sex with women, and recently I've found it hard to have relationships in general. And I'll admit, I've been curious like many other people, God I sound naive, but I've searched porn before and I don't like it. I've watched amateur videos and that's what I've always wanted but never been able to get and it's always been hetero sex. The thought of two women or two men do nothing for me and when I think of it, I try to see the positive side but I just can't. I don't know. I'm just a person who likes solitude and am very independent. I'm just guessing all my problem is just something I'm psyching myself out about. So, does it seem there is any form of bisexuality in there...? I've also messed around with the idea that I may be asexual (which means you have hardly any sexual attraction or none at all, which sucks). Or am I just overthinking? Thanks. :)