Dear doctor, Had unprotected intercourse on 25th aug ( with failed withdrawal method).. ovulation was supposed to be on 28th (give or take 2-3 days). Had ipill after 32 hrs. Expected periods was to be on 12th sept.. today on 17th , nothing has happened..no withdrawal bleeding or anything. I last checked for pregnancy on 13th sept, it was negative. Do I need to check for pregnancy again?when should I expect my periods?