“Premenstrual spotting”, also known as luteal phase spotting, may be as a result of lower-than-normal progesterone levels. And yes, egg quality and progesterone can be related.
However, egg quality isn’t the only explanation for spotting. There are many other possible reasons for spotting in the luteal phase, including: intrauterine polyps, fibroids, a thin uterine lining, progesterone receptor deficits, and bleeding from the cervix…so I wouldn’t take luteal spotting as a certain sign of egg quality compromise!
But I would look into it further, to see why it might be happening to you.