Vitex

I took vitex on January of this year and I got a BFP but AF came 3 days later. February my period was just different very light then heavy. Not the usual for me. 
Now March my period came 6 days late! My pregnancy test had a faint line. I didn't really want to get excited because of January and my "BFP" 
So now my March af is completely different.
My periods are never late or this painful with heavy blood. 
Can it vitex be the reason why?