It's always best to consult a practioner when using vitex. In saying that, there is conflicting information regarding taking it. I consulted my tradtional Chinese herbalist and he said to take it til pregnancy. Whilst the information I read about it suggested taking it from the end of af until ovulation. Vitex helped lengthen my luteal phase. For more information check out YouTube, practioners are on there explaining how it works and how and when to take it.

Hth, all the best in your ttc journey.