Pill/ late period

María

I took Plan B Oct. 30 , 2017 then my period came one week late , after that my periods didn't have a specific day they were going to start from it on January I had sex but after my period came and nothing happened , now it's February and my period is 6 days late is this bad ??? Btw I have protected sex 2 days ago and I only did oral the end of January and February and I am in so much stress and haven't eaten right and etc.