Not entirely sure of your situation and am not here to judge. I think it is only fair to your husband and the baby’s biological father to know the truth. It is a tricky situation and will definitely not be easy to work out. But it is best to be handled as early as possible rather than it being revealed at a later time due to whatever situation. The betrayal and lost of trust may be even more intense with time. In my opinion, there is really no “right time” for such revelation and it should be done as early as possible. I think you will need to be prepared to give your husband time to digest and process the information. Also, consider what are your thoughts on this situation? Do you still love your husband? What do you think is the best option for you? Consider marriage counselling if both of you are open to it. Sometimes, having a professional third party to help work through issues will be better than trying to resolve things on your own.