How long is plan b symptoms supposed to last ?

Ive been having sex every week by pull out. On saturday he nutted on me by accident and i took plan b on the same day. The first 24 hours i had no symptoms. Now , its the third day and been feeling extra tired, have a loss of appetite, anxious, and weird stomach feeling. My period doesnt start until the next week . When should i worry? Is this normal ? How long the symptoms are suppose to last ? This is my first time taking plan b.