Not at all. Pre-scientific outlook on fertility was inded the notion that the semen was a form of seed and the womb akin to soil. But from there, your interpretation goes off the rails. Theologians of the day did NOT consider the semen as already present human life, rather most of them believed that transformation occured later. I suggest you peruse the forums here on abortion related “ensoulment” arguments where pro-aborts attempt to discredit the catholic pro-life stance by citing (accurately) saints and early fathers who speculated on exactly how long after the ‘seed was planted’ it took before ensoulment occured (i.e. a human was formed). The pro-abortion crowd often labors under the impression that because the early church didn’t initially recognize early abortion as murder that it didn’t recognize it as sinful. That, as any serious investigator soon learns, is not the case. The Church has always condemned abortive procedures (which are not modern) as sinful, even when the primitive biology of the day didn’t yet recognize it as the termination of a life, but more like conventional contraception.
Church condemnation of contraception was, thus, the original foundation for her consistent rejection of abortion. The later biological advances in understanding that allowed us to recognize abortion as the killing of a distinct human being came later.
So no, I’m not having it both ways. A modern articulation of NFP is simply not possible in the vocabulary and scientific comprehension of the EF period. The thread premise is entirely faulty.