I'll entertain the idea that personhood applies to a fetus for the sake of this argument.

By the same logic the following things are also murder or at the very least attempted murder:

1. Refusing to donate tissue/organs after death. After all, you aren't using them anymore and there are other lives at stake.
2. Refusing to donate blood, tissue or organs while you're alive to save your dying match.
3. Consuming alcohol before impregnating a woman, affecting the quality of your sperm and ultimately causing a miscarriage. You poisoned your child to death.
4. A woman doing anything unhealthy with her body before she knows she's pregnant, leading to a miscarriage.

If you are pro-life because you believe the unborn are full-fledged persons, but don't believe that anybody, dead or alive, should be forced to undergo medical procedures for the sake of someone who has already been born, you believe in telling the government they may decide some people are more important than others and a person may be forced to make certain medical decisions for the sake of one of these more important people.

Your alternative is deciding that everybody should always prioritize others above themselves, meaning fertile people need to be banned from smoking, drinking, junk food and all sorts of prescription medications, just in case.

That doesn't sound very libertarian, does it?