My Naturopath gave me Premular - exctract of vitex angus-castus (chaste tree)

My period is now late making me think that I might be pregnant but reading up on Premular it could just be my hormones levelling out. My period was always 27 days. I'm wondering if I should stop taking them.
I also read that it reduces your LH levels???

Has anyone used Premular? Did it work for you or make things harder and more confusing.

Thanks in advance