Should I move on?!?

my girlfriend ( she says she loves me and I like her too but it’s not official) invited me to her friends birthday party. My gf has lots of guy friends and she sat with them. When I tried to sit with her she would move to a different table bc she wanted to be with her guy friends. I got a bit mad. So I decided to not pursue her no longer that night. So I hung out with my friends most of the time and kinda ignore her. She seemed to be having a good time with her guy friends and so I got a bit jealous. After eating, we went to skate. She still hung out with her guy friends. I caught her looking at her guy friend lots of times and she was with him almost the whole time. She occasionally saw me and came with me, she would lay her head on me but would look at the other guy. She would leave because I’m not a talkative person and she needed to talk to someone. So she left me and then went with her guy friends again. At the end of the night, she left with them. I got home 40 minutes before her. She was riding with her friend but I don’t know if she left with that same friend or if she left with the guy she was starring at. I keep thinking she cheated on me bc she got home 40 minutes after me (we don’t live together). I haven’t texted her all day today. She shared a video on Facebook captioned (How I feel when I mess up and regret it). I don’t want to text her and complain because part of it was my fault for not being closer to her. I don’t know what to do now.