Suggest Treatment For Red Rashes On Chest And Face

I recently took a Plan B one step pill last night around 12am. I woke up this morning around 8am and notice i have a red rash on my chest and face. I have read all the information that is provided on the box. However, the side effects does not say anything about rashes. In addition don't even think it will be consider a side effect? Although, it is very itchy & red and i am concern since i have never took a morning after pill before. Your help is much appreciated.

Thank you!!