As the women on the pregnancy forum told you, you're already pregnant.
Birth control pills do not end a pregnancy, they prevent one.
Since you are already pregnant, if you want to end this pregnancy, you will need an abortion. An abortion will kill the fetus; you will not give birth to a baby; it will die. I'm pro-choice but I feel like I need to tell you this since you seem very ignorant, and I don't want you having the wrong idea about abortion. That happens to too many women; and an uninformed abortion can lead to post-operative stress and guilt.
Please, let us know what's going on.