Can't get pregnant again 8 months after Miscarriage? As per the doctor everything is perfect so what the delay is?

Patience needed. You have already proven that you are capable of getting pregnant(miscarriage) thus ovulation and patent Fallopian tubes are not an issue. Fertility MD's do not usually start an assessment on 26 year old patients like yourself unless you have gone from one to two years of unprotected sex and not gotten pregnant. Give the 'tincture of time" a chance to work.