Progesterone Oil Shot to Kick Start a Period

After my second miscarriage and first d&c my period needed a kick start. So, my OBGYN suggested a progesterone oil injection. I received the injection August 3rd and have not gotten a period yet. My OBGYN said I should my today (the 9th). But, I have been researching and articles are saying it takes as much as 2 weeks. Do you have any experience with having this injection to kick start your period? Have you heard it not working before? We are anxious to try again but just waiting for my darn period :) Any information would be greatly appreciated.