Pup don't despair these intrusive thoughts are just convictions that us OCD sufferers are lumbered with.I still today when I drive my car feel as though I have run sombody over without knowing.......How bizzare is that......and I would have to go back and check,and thats not once only...........so when I go back and check and also inspect my car and i find nothing I realise well its my OCD, but I sincerely understand the intensity at the time. Stay focused and my recomendation is not to panisc and stay atuned with the rhythm of your breathing in these intrusive cases.