Hi welcome to H.C.M.Forum. there is every chance of pregnancy
because the period you had intercorse is in the unsafe period. means between 11th to 20th days. any how you gave her preventive tablets so dont worry.
if she croses april 11th you should be attentite. and get the urine pregnancy test. if it is positive she is pregnant.
if that is the case i advise you to see a doctor.
then you need to get the blood test