Vitex side effects? Help?

Hello all. I started taking Vitex around Sept 2 after reading a blog stating that it helps with fertility,PMS, & irregular periods. Well my period was supposed to start on Sept 9 and it’s not here. My periods are sometimes irregular but this got me freaking out because I seen on another post that if your CD are like 28-33 then you shouldn’t take Vitex cause it’s the last thing you wanna do and my CD are usually 30-33. Today is gonna be my last day taking it but if you’ve experienced this how long did it take your period to regulate after taking it? I’m not pregnant cause I took a test on the 9th and it came back negative. I was wishing I was pregnant cause I had a ton of symptoms before my period was even due.