What Causes Difficulty In Conceiving After Abortion?

Good day. I had an abortion in 2012 And have been on cocontraceptives which i had stop the middle of 2013 up till today i am battling to fall pregnant at the moments i have a missed period for 2.5 weeks and clots are starting to come out of me like when i had the abortion what cause this be and what can i do?please help.