It is completely normal. Don't worry.
The "bulb" is the remnant of the follicle root that is shed by ALL people, whether they have male pattern baldness or not, in the normal course of hair cycles.
Hair shed WITH a bulb indicates it was ejected as part of the normal shed/rest/regrowth cycle that all humans experience.
Hair shed WITHOUT a bulb indicates that the hair was not shed, but rather was somehow severed from the scalp for other reasons, either being cut, broken off, etc.
The bulb is NOT the follicle itself, but it is an indicator of an intentionally shed hair just as a snake sheds its skin. Seeing a bulb is a sign that the follicle said sayonara to the hair shaft it was growing, and let it go, in anticipation of a rest cycle, then commencing regrowth on the next hair that will replace the shed one.
When you go through periods where you shed more hair than is being replaced, the official terminology for this is a "syncronized shed" and it is very common. Some have attributed such sheds to seasonal events, kind of like how a dog sheds hair fairly heavily at certain times of the year, but then reverts to a more light shed between the heavy seasonal sheds. Although humans aren't animals and don't have a "winter coat" of hair, we still tend to have some of the genetic predispositions towards periodic synchronized shedding.
