So your girlfriend is acting weird, and you're beginning to wonder if she's cheating on you. Maybe she is hiding her cell phone from you, or not answering calls in front of you. Or maybe she's texting a lot but when you check her phone she has erased all of her messages. She is probably also acting distant and not responding to your advances the way she did a few months ago. If you have tried to confront her and it has only ended up in a fight, then it's time to figure out once and for all what's going on with her and your relationship.

Three common ways to figure out if she's cheating on you are:

1. Log in to her Facebook or Myspace page. Chances are, if she is cheating on you with someone they are probably on her friends list. If she is also acting strange any time you catch her on the computer, she might be trying to hide an online romance. Or she could be using Facebook or Myspace to chat with her lover on her phone and that's why you can't find any evidence of text messages. If you know her password, checking her account will be easy. But be prepared just in case she changed her password - you will have to do some sleuth work to figure out the new one.

2. Check her instant messaging profiles. Snoop around on the computer and see if you have instant messaging installed. Programs like Skype, AOL Instant Messenger, or Twitter can all be used to chat. Facebook and Myspace also have their own instant messaging programs. A lot of these programs leave traces behind and sometimes the chats can be saved - it is possible that she is keeping records of her romance right under your nose and all you need to do is check for it.

3. Check phone records. If you are both on the same cell phone account you can call the cell phone company and sometimes get a record of text messages. You can also check the calling records and see if there are any numbers that are calling that you don't recognize. You can put any of these numbers into a Reverse Cell Phone Lookup and find out almost instantly who the person is. Even if you know everyone that she is calling, be aware of any numbers that she is calling at odd times of the day, like when she should be at work, for example.