Should I Be Concerned About Late Period With Mild Abdominal Pain And Tender Breasts Despite Taking Plan B After Intercourse During Ovulation?

On the 22nd of March I had unprotected sex which was supposedly my last day of ovulation as a result I took a plan b, currently im having slight lower abdominal pain and tender breasts. My period was suppose to come on the 1 of April but I haven't seen my period as yet. Current I am very concerned as to what may going on and need some consolation.