Whether Christ's body was formed in the first instant of its conception?

Objections

Objection 1 : It would seem that Christ's body was not formed in the first instant of its conception. For it is written (Jn. 2:20): "Six-and-forty years was this Temple in building"; on which words Augustine comments as follows (De Trin. iv): "This number applies manifestly to the perfection of our Lord's body." He says, further (Questions. lxxxiii, qu. 56): "It is not without reason that the Temple, which was a type of His body, is said to have been forty-six years in building: so that as many years as it took to build the Temple, in so many days was our Lord's body perfected." Therefore Christ's body was not perfectly formed in the first instant of its conception.
Objection 2 : Further, there was need of local movement for the formation of Christ's body in order that the purest blood of the Virgin's body might be brought where generation might aptly take place. Now, no body can be moved locally in an instant: since the time taken in movement is divided according to the division of the thing moved, as is proved Phys. vi. Therefore Christ's body was not formed in an instant.
Objection 3 : Further, Christ's body was formed of the purest blood of the Virgin, as stated above (Question [31], Article [5]). But that matter could not be in the same instant both blood and flesh, because thus matter would have been at the same time the subject of two forms. Therefore the last instant in which it was blood was distinct from the first instant in which it was flesh. But between any two instants there is an interval of time. Therefore Christ's body was not formed in an instant, but during a space of time.
Objection 4 : Further, as the augmentative power requires a fixed time for its act, so also does the generative power: for both are natural powers belonging to the vegetative soul. But Christ's body took a fixed time to grow, like the bodies of other men: for it is written (Lk. 2:52) that He "advanced in wisdom and age." Therefore it seems for the same reason that the formation of His body, since that, too, belongs to the generative power, was not instantaneous, but took a fixed time, like the bodies of other men.