Heavy and painful period on Vitex/Agnus castus

[Niru17]

I started taking Vitex ( Also known as Agnus castus/Chasteberry) 4 days ago. I got my periods right after 3 days of taking it. Periods are really heavy and am passing small clots. I'm confused if vitex actually works like this or am having opposite effect. Do you think Vitex can stop a period by 5 days? We planned for a trip this weekened and am worried if Vitex doesn't stop bleeding on time. I had lots of hope while taking this..Thought this herb would help me getting pregnant. It's hard to even imagine discontinuing it. Did anyone of you take Vitex anytime?