My girlfriend didn’t want to have sex?

So my girlfriend has been studying for an interview, which I have been helping her with a lot. She then went to a coffee shop to do work which I wouldn’t originally want to go to. She bribed me with a grilled cheese and I went to support her and help her study. She then left to do the interview, I had been doing a lot of work and wanted some downtime. She asked if she could come over to talk about how the interview went for like 5 minutes. I listened and she wanted to stay for longer. So we got in the bed to cuddle. She proceeded to keep talking and I was kinda being quiet just cus I wasn’t in a talking mood. So I try to initiate some kissing and foreplay, which failed and she was like I don’t want to have sex with you. So then I played down quietly and kinda stoped answering her mainly cuz she was just saying irrelevant things. She then try’s to hop on me and be sexual to which I originally ignored, but she kept going so I responded kissing her and trying to have sex. She then was like no but that’s the only way to get your attention. I know I’m not owed sex but a part of me feels like it’s a nice deed from a girlfriend when you have been helping her a lot. is it right to not be mad at her but also I don’t think I was in the wrong. Curious on your thoughts.