Hi! A Good Evening To You Dr. I Had Just

Hi! A good evening to you Dr. I had just finished my last pill of vissane two nights ago this is my third night of taking no pill but earlier i had an unexpected s*x with my partner. Does that mean i need to start another new pack but i want to change from vissane to althea, is it good ? And is it safe ? should i wait for my period before i start to take a new pack ?