The woman i love and about to marry is having an ...

You absolutely should confront her now. Let her know that you know about her affair and feel deeply hurt by her betrayal. If you two decide to work on your problems and move forward together, then work on it before you make the life-long commitment of marriage. You want to feel sure about your love for one another before taking that step. Good luck!

Hi,
If you are 100% sure she cheated, leave her as soon as you can..... let her know that you left cause you couldn't tolerate it.  Don't confront her, it's useless and will do no good. Thank God you found it on time, move on and find someone that has similar values to yours.  If you were married I would advise to work it out in a trial to save the marriage, but you found it on time, so leave her as soon as you can.... a 2nd chance will, most probably, lead to a 3rd chance and then a 4th and a 5th.
Best regards,

You talk a lot about her, but I think the first thing you need to do is to decide what you want to do, do you want to stay and get married to a woman who cheated on you or not. Your focus now should be on yourself and figuring out what you want.

The next thing you should do, I think is to cancel the wedding and spend some time without the stress of the wedding to figure out with her what were the reason for her betrayal and how the two of you can learn to communicate and to share a life without this happening again.  

You need to cancel your marriage to her.  She is not sure about marrying you that's why she's fooling around with another man.  You are going to make a very big mistake if you'll marry her.  You're not stuck, you don't have the commitment to her yet.

i got a better idea get her on that show cheaters that'll be a hoot first of all you love her she don't love you i know it hurts but shit dude just think do you love women sleep with other men whatever she has in common must not big.or probably yall are going through a problem and its hurting the relation i don't know your not telling me much dude.but anyways do what makes sense to you and by the way go cheat swear to god it'll make you feel much better.

Do not marry her , and be grateful you found out before you gave her your last name .   She's broken the bond , trust the foundation for a relationship .   Break your engagement and tell her why .