You are worrying about your relationship.
You really wish that there were signs you could see if your girlfriend wants to break up with you.
Even though you and her have been in a long and, what you thought was, a happy relationship, lately things just haven't been the same.
In fact, she seems to be giving you the cold shoulder very often.
You can't quite pinpoint what the problem is, but you would like to fix things - you still love her.
The good news is, there ARE signs your girlfriend wants to break up with you, and if you can identify them you will have a REAL chance to get her back.
Just be more observant over the next few days, and as you see these signs, fix them immediately, in other words, talk to your girlfriend about them and sort them out straight away - she will probably like the fact that you're taking her feelings into consideration.
If she seems reluctant to spend time with you, is always ready to start an argument with you, or prefers to be with her friends more than with you, then these are definitely signs that something is wrong.
Sit her down and talk to her.
Tell her that you love her and want to do things to make her happy, and she must let you know whatever it is that you are doing wrong.
Then listen to her very carefully, even if she gets mad with you, be patient and hear her out.
There is a good chance that she will be very happy that you have noticed that there is something wrong, that you are willing to do something about it.
This will be a good point in your favor when she thinks about it and decides what to do.
In short, when there are signs your girlfriend wants to break up with you, don't just shrug it off - take steps immediately, communicate with her, and you have a good chance to win her love back.