I've done this thing too along with avoiding cracks on the sidewalk but not to your extent...do you enjoy this or do you get anxious if you do not do it? Can you stop this behavior pattern whenever you want to or is it getting out of control? Oftentimes obsessive behavior patterns are the result of someone trying to repress overwhelming subterranean emotions/feelings that they are not capable of currently consciously integrating. Therefore if this pattern is controlling you and causing you anxiety and it seems to be growing, counseling with a professional may be advisable. On the other hand, maybe it's not this serious.