We are wondering if someone can give us advice on bedbug worries?

we found 3 small bed bugs on our sons couch in his room.we threw the couch out that second then we steam cleaned the floor and sprayed the entire room with lysol.there is no other furniture in the room at this time (we were in the process of redecorating) We have inspected the room to the best of our ability and have not found anything but we are worried that we may not have effectively solved the problem.We do not want them to come back.Can someone tells us if we can rest ured or is there anything else we can do to make absolutely sure.