how bad does stress affect your period?

If I'm even in the slightest bit stressed my period is always late, it currently is right now. I just moved and I'm having my regular pms problems; pimples, moody, and cravings.
( specific things I crave every month ) All my usual stuff. I start to stress about it being late and it delays it more. I always use protection and am very cautious with having sex, so I know I'm not pregnant. Does this happen to anyone else?