OCD can stand alone as its own anxiety disorder, or can be a symptom of generalized anxiety. Movies like As Good As It Gets and The Aviator show a very small idea of what OCD is and often we think those are the symptoms. They can be, but every OCD is different. The key is anxiety that causes you to obsess about things (in your case obsessing that you have checked everything) and compulsions (in your case going around AND checking those things) are what OCD is all about. Phobias are extremely common with this disorder. My mom was so sure I didn't have OCD when I was diagnosed because I didn't show those common symptoms - my room was always a mess, I never openned and closed doors or spent hours writing and re-writing homework. But digging into it and finding out how MY symptoms related to those things made me realize that yes, in fact, it IS OCD after all. I've been in treatment for years (both meds and behavioral therapy) and now my OCD is very minimal and totally livable - it only gets bad when I am sick or have severe anxiety about something.
You say "so what" but being late to work to check things isn't good. Your boss will eventually probably have a real problem with that. You will be amazed how much better you will feel if you get past it! And know, you are not alone. This is a very common and totally treatable disorder. Some don't even need meds for it... that depends on severity.
Take care,
LizardL8y