You might be describing a diverticulum attached to your urethra. THe "long thing" may be the urethra, and the "marble" may be the diverticulum, which is a pocked along the urethra, which can sometimes get filled with urine or pus. It is not normal and is usually treated by excising it surgically. ALternatively, if it is in the labia itself, it may be something called a "Bartholins Gland" that is enlarged. THis too can also be treated surgically. Get an evaluation from a gynecologist, who should be able to identify this.
Dr. Hoyte
just to add cycles have been 38 days since october until this month where |I am still waiting.