Talk to Gynecologist on Missed Period/ Gynaecological

Aoa doctors. Its a gynaecologist special post. My friend missed her period due june 25 n its July 1 now. Shes afraid she might be pregnant(its her first time). Although she carried out her strip tests at home n it was negative but shes really worried about the delayed period as she doesnt want to conceive rn (her personal issues) n shes getting symptoms like nausea, stomachache, constipation. Is there any medicine that could immediately bring on her menstruation? Pregnant OR not, just the medicine? Without any major fertility risks? Also she cant go to the hospital for a physical examination so we're totally dependent upon online prescription. Kindly suggest a medicine.