Are you genuinely not already aware of the biological difference between a (haploid) gamete and a (diploid) organism? This is like 7th grade science stuff, so I want to understand if you're questioning whether there is a difference or whether the difference matters.

Zygote, embryo, fetus, infant, toddler, adolescent, and adult are all different stages of the life cycle of a human organism. Gametes are not. Before fertilization, there are gametes. Unless fertilization happens, no organism comes into being. But once it does, it is the same organism from then all the way until its death. This is a biological reality, not a philosophical one.