I am with you. I once saw a Dr Oz show in which he was touting Vitex saying its so great for relieving PMS symptoms and getting your cycles normal. It was the biggest mistake I ever made and threw me off worse than ever. Never again.
I am a big believer in taking a multi vitamin, CoQ-10 and vitamin D. Those to me, are really "safe" and shouldn't throw off your cycle at all.
Really we have to be SO careful with certain herbs/supps...they can do more harm than good sometimes. I learned my lesson after taking that Vitex too.