I Have No Idea What I Want

In the past 3 or 4 months or so I have come to terms with the fact that I am bi after denying it for a long time. Now that I am more comfortable with the idea of being attracted to men it has sparked my curiosity about pursuing a relationship with another man.My problem however is that I currently have a girlfriend of over 3 years. I have told her about the fact that I am bi, which kind of bothers her but she is willing to at least act okay with it and not let it mess up our relationship. My girlfriend means a lot to me but I cant help this nagging feeling of wanting to try being with a man.Im a very logical person when it comes to lots of things so Im not the best at dealing with emotions, especially my own. I cant decide what I want to do. Im afraid that I will give into this nagging feeling and then regret it once its all said and done, or that I will end up not following it and regretting it later.I just cant figure out what I want.