Talk to Gynecologist on Periods Delay

AOA Dr. Married year ago trying to convince but can't visited many doctors different medicines letrazole bristazole rozolet has been used but not conceived yet this month first time my periods are 7 days delay my menstrual cycle is of 25 days including those 5 days and 2 more up 7 days delay checked through strip different days all time negative please suggest should I go for blood test or not after how many days of missed period I can't get accurate result through strip. jazakAllah