Define that life begins with conception.
What do you think of my bill?
As a legal question (since it's a bill), have you considered the following? I presume that your bill would define certain human rights to the embyro at conception. Living cells regularly fall off the embryonic cell mass as it grows. Those cells are not themselves a new genetic organism, and I presume that they would not have legal rights in your bill since usually they die off like any other cells our body sheds. Yet, when then come from the embryo as stem cells there is a chance that they develop into a new and separate human that we call an identical twin. Now the question: if legal life begins at conception how does one determine the beginning of legal life for an identical twin without granting legal status to every cell that falls off an embryo?