Why is my girlfriend in a bad mood if she doesn't reply to the message?

There are two situations when you don't reply. One is that your girlfriend doesn't have you in her heart, which is unlikely. Another possibility is that girls generally don't like to reply to news. When they saw their boyfriend's text message, they were elated. They only know that their boyfriends care about themselves and don't consider their feelings. So you should relax. Since you sent her a text message, you care about her, and she cares about you, but in different ways. I hope I can help you.