I have friends who always thought their DH/DP etc would fall to pieces during the big event, but turned out to be a tower of strength for them and coped amazingly well. If your DF is a bit squeamish with blood, he doesn't have to go down the 'business end' of things either - or maybe once he is there it wont bother him. have you sat down and talked to him really in-depth about what exactly his fears are in being your support person etc? It may help him learn to cope with it all kwim? or even once you start pre-natal classes he might get a better understanding of what is expected of him, cause that may be one of his fears.