If personhood becomes legally granted at the time of conception, do we all age 9 months?

Any child born before Oct. 1 would be a tax deduction for the previous year.

Could pregnant women travel “solo” in HOV lanes?

This depends on what species of people you are. A court just declared that hippopotamuses are legally people, and they have a gestation period of just 8 months. So if you are a hippoman or hippowoman, your age would be adjusted by just 8 months.

Cite: Hippopotamus - Wikipedia