trust me if yo hadnt have touched the egg it was doomed anyway, i dont know where yo come from or how hot it is their but the egg would have needed to be kept at a steady 37.7 degree celcius temperature anyway, and it would have needed turning 5 to 9 times a day, and when the chick hatched feeding it wold have been very difficult,
the egg will start to rot if you keep it however if you boil iit, it will keep for a long time, noto recommended to eat it though lol however on saying that i dont know where yo are or what contry but it is illegal round here for anybody to keep wild bird eggs so check with your laws about how they stand
the chances are the egg either fell from a nest or a bird stole it from the nest and dropped it, if the egg was very warm when yo found it the chances are it was only recently took or dropped,
sorry coldnt have been here to answer you but really their is nothing yo could have done for such a fragile egg without the specialist equiptment that would be needed, lamps work for chicken and duck eggs occasionally but for robin eggs and other fragile sorts their would have been little or no hope of it surviving,
but at least you showed concearn over the egg,