Itching, Vaginal Discharge, Sonography Showed No Pregnancy. Is Canestin Ok?

Dr., my last month periio was delayed from 4th august to 13th.on 13th started to have periods but scanty and light flow in spotted form moreover.taken 2 BHCG with 1.2 count as result.consulted doctor on 9th september when started feeling some itching and white vaginal discharge .she asked to get a bllod test again and TVS sonography which resulted NO PREGNANCY and blood test againg with 1.2. she suggested canestin for having a yeast infection , duphaston for 3 cycles,Doxy 1. I do not want to get pregnant so are these test ok for confirmation? is this vaginal cream ok to be taken? can duphaston lead to pregnancy chanes , i want to have regular period and no pregnancy. was the scanty bleeding implantation bledding if these test are not absolute.