Help Please ..

Brittany ❤
Goin On 4 Weeks I Took Plan B , Within 19 Hrs && I Been Feelin Normal Every Sence Then & I Read That It Can Delay My Period && Yesterday Was The Day My Period Suppose To Come . & it Didt & I Took A pregnancy test Today && It Came Out Negative . 
So Dose That Mean My Period Is Delayed ?