Talk to Gynecologist on No Periods After Duphaston

I had lets (letrozole) 3 tablets from 3rd to 7th cycle day. On 11th day IVF c 5000 shot for ovulation (20 mm folicile). Duphaston started same day (11th day). Dr prescribed duphaston for 14 days. Now after stopping duphaston its been 4 days no periods, no signs and symptoms only just minor cramps, usually i get periods with so much pain. I tested strip test 5 days before but it was negative and it was a very early test as well.

When shall I expect my periods or when should I go bhcg test? I am in a very confused stage.

I shall wait for the periods or go for the blood test bhcg.