My girlfriend is not online on QQ today, and she doesn't answer the phone or reply to text messages.

1. Influenced by the outside world, someone talked to her (including her parents) and asked her to think about this relationship with you.

2. Questioning and your possibility to continue, life pressure and other factors.

3. If you are emotional, this possibility is less.

4. It may be a grievance or dissatisfaction with the status quo.

I can know from your girlfriend's behavior that she is not stupid. This may be the main attraction for you. All you have to do is keep texting and promise something. You must pay more attention to her. Note that girls may break up at this time.

I hope it helps you.