Okay so i had unprotected sex april 25th and right the next morning i took plan b so my period was supposed to start may 1st but it's may 5th now ?

Delayed ovulation: the way plan B works is that it delays ovulation and can therefore make your period occur a week late after the amount of progestin you ingested finally dissipates from your body. sometimes some people take plan B too late, in which case you could be pregnant and so if a week goes by without a period, I would check a pregnancy test.