Is this cut bad?

ok i accidently cut my self with my knife, i cut my thumb rite bellow the mid-knuckle. i looked at it and at first it didnt bleed but i could have sworn my bone beacause wen i moved my thumb i saw sumthing very white moving as the thumb moved. then i just went 2 the doctor, two hours later and the doctor just took the bandage i put on there of looked at my thumb and i told him i thought i cut to the bone but he said i didnt even tho it didnt open the wound to look so then he pored iodine on in and then some glue, he didnt even open the cut up to clean inside of see how deep it was. so my question is could i have cut a tendon or something and not know it and later have bad damage? and just put anything u can that would help me some beacuase i dont think the doctor did a good job and there may be more damage....thanks