That just sounds like you're cycling between your pill reserve and not infinite pills.
You can hold up to 3 pills, 4 with Little Baggy, and once you pick up with a full pill inventory, it drops the leftmost pill and lets you take the new one.
Yes. But normaly you can only pick up one at the time and then you have to waite for another one to get dropped. In this case, you could pick them up one after the other, besides you wait a moment and it despawns like every other item.