My girlfriend seems to be okay with not being able to chat to me for a few days, is this normal?

I know what you're feeling dude. Sometimes my girlfriend does this but only when she's mad at me and it's only for a day or less. She usually turns her phone off. But yeah, for her to do this is really not normal and very mean. When you see her just ask her if she cares if she talks to you. Easy solution dude, don't be scared. Most of the people on here asking questions like this or bullying and such are just scared to confront a problem. It's not hard, try it :)