will Endometrin delay my period? HELP Please!

[Moms2b]

Hi everyone! I am on my first month of endometrin to help my short lp, I am taking 100mg 2x a day. I am wondering if this delays your period from starting? I am 11dpo, no period, usually comes by day 8dpo but a BFN this morning! I had some brown spotting on 9dpo and though it was the start of me period, but nothing has followed?!?
When should I stop taking it? I am happy to say this my longest lp ever! so it has worked...
Thank you!