This is very sad. If you can forgive her thats fine(easier said than done), hopefully she loves you just as much as you claim you love her.

On the other hand,
Its even good you have no child with her yet so return her to her parents or let her go peacefully and move on with your life. Marriage is too important to play games with or to take chances

There is no way to hide a 5 month old pregnancy forever dont be deceived looks to me like she just used you as an avenue to bring herself and the baby abroad. Old habits die hard