My advice is to get yourself to the dr, explain your circumstances and ask for a quantitative blood test. At this early stage, they may be able to get a clearer idea of timing based on the level of HcG in your blood. Some early ultrasounds may help as well. But you need to do this as soon as possible because the levels go up so steeply that they stop being informative after a certain point. You may or may not get a clearer idea after this but IMO it's worth a try. This info might put you in a better position to discuss this with either man if you then decide it's what you want to do.

Big hug - there must be a lot of uncertainty and worry for you right now. Try to be gentle with yourself .