Am 27yrs, height: 5'3ft, weight: 60. I had ma last period on d 1 of April nd i had sex on d 11th of same mth,thou i used a preventive pill dat day. Today is 29th of same mth nd av nt seen my period. I want to know if it's not to late to use gynaecosid pill nd how effective wil it be at dis stage?