Temporary shrinking (aka turtling) after a workout is fairly normal for some men. It's generally a sign of an intense workout. It could relate to overtraining, but you'll have to interpret it with your other PIs; see this article:
Physiologic Indicators (PIs) to Help Growth! - Penis Enlargement Gym
The shrinking isn't permanent, of course (this is an enlargement forum
) . . . But if you have negative PIs, be sure to lay off the intensity - or else you can cause unnecessary problems.
Your glans will typically grow with your penis, but you may have to do glans-specific exercises in the future. As for when should you expect to see some growth, there's really no telling - some men gain in one day, others never gain.
Hope this helps!