Is there or was there a form of birth control that allows the baby to implant but the chemicals kill it after?

I don't know where I heard this or if it was an old form of BC, but I heard that it was something you put in your uterus maybe? Let me know if you have any idea. It isn't an IUD is it?Is there or was there a form of birth control that allows the baby to implant but the chemicals kill it after?
It's not the IUD. The IUD keeps the egg from implanting in the uterus.Is there or was there a form of birth control that allows the baby to implant but the chemicals kill it after?
The IUD stops implantation, the combined pill stops ovulation, and the mini pill stops ovulation and/or implantation. The only pill to kill an embryo after implantation is the abortion pill.
It isn't a form of birth control. That is the abortion pill.