bleeding again

Shellby

So i was having bleeding for nearly 2 month's went to the ER they gave me birth control to get me on a regular cycle and to stop the bleeding. I did as the Dr told me which was take 2 pills a day till you stop bleeding. Then take only one. I stopped bleeding and have only had 2 days with only having to take one pill. Because my husband and i have not had sex for 2 month's of course we had sex many times. but today i started to bleed with cramp's and i noticed that i had grey matter tissue come out when i wiped not big but very small. The Dr told me when i take the placebo pills i should have a period that week. MY QUESTION IS COULD I HAVE STARTED MY PEROID EARLY? OR COULD I BE HAVING A WITHDRAWAL FROM ONLY TAKING ONE PILL NOW? And i thought birth control stopped peroid's till the placebo week? Im 29 this is my first time on the pill and it will only be for 2 months as we have been trying for a baby for a year now.