Upt negative, period dh lewat 17 hari

Hi mummies... Nk tnye... Saya da buat treatment kesuburan... Doktor prescribed kn letrozole... Pastu dlm the 14th day kne amik 1 suntikan yg cucuk kt perut... doktor sruh bersama pada hari 14th, 15th and 16th... And check for pregnancy semggu lepas expected period to happen... Tp skang nie period dh lewat 17hari.. n upt still lg negative... Please advise... 😔