I cheated on my wife during third trimester. It was random but i did it twice. Its eating me up! Keeping mum seems like my best option...any thoughts?

Cheating is cheating. No one deserves to be cheated in a marriage and specially not when they are pregnant. This is a truth that needs to be confessed and you need to face the consequences of your actions. Now, it depends on how your Wife reacts and what she decides on. The two of you needs to sit down and find a way forward.