If the repeat test is negative, it is more likely that she is not pregnant, yet, if you want definite confirmation, you can get serum beta-hCG measurement to be conclusive. Delayed periods may be caused by a variety of reasons- pregnancy
disturbances, weight disturbances, polycystic ovaries
, emotional trauma and drug interactions. Please follow your doctor's instructions and go for any means of sterilization
if you do not wish to have any further children. Take care.