Should I have something to worry about with this girl? Or am I insecure?

I've been talking to this girl for 3 months now. She's bi, I'm a . We are taking things slow but for the past month and a half we started really liking each other. Now she's slowly flirting in a dirty way with me, calling me beautiful, etc etc. We talk almost everyday. I really like her but my past relationships have all been crap. My insecurities run deep because of this, and I have a bad temper. I try not to let her see it but it's getting worse for me. She was talking to me tonight and she was responding very slow, so I thought it wasn't a big deal because sometimes it is like that, she's busy and such. She kept coming back and saying "I'm so sorry!" and stuff like that, so I shrugged it off. Then I go on facebook and she posted a funny status of a conversation between her and her guy friend that they just had 5 minutes ago when she hasn't responded to me in a half hour. He's always blowing up her page and though they never have flirted from what I seen it still enrages me. Should I have something to worry about?