Progesterone: Am I doing it wrong?

This was my first cycle using the progesterone suppository. I took a pregnancy test one day after my missed period: negative.

So I stopped taking the progesterone. Still no period in sight. How long after you stop progesterone does your period start? Is this just going to mess up my cycle?

I didn’t realize I have to stop the progesterone in order for my period to start again. I feel like my doctor didn’t give me much info about how it all works. And insight would be greatly appreciated!