Hello and Welcome to PC. I am so glad you joined us here. Things could be going on with your GF that are just normal everyday things or yes it could be another man. There is really no way to tell except by asking her, getting her to talk to you, telling her you need it laid out once and for all, after all the truth can only come from her, you can go crazy imagining all sorts of things. Talk to her soon.

Sincerely,

Roxy