When determining egg quality, examine your menstrual history. Ovulation generally occurs around day 11 or 12. Late ovulation is not a concern. Early ovulation however, could mean poor egg quality. Although not concrete, some women ovulate as early as day six. Ovulation tests will help to determine what is normal for your body.
If the left over follicle is not producing enough progesterone, it could indicate a low quality follicle. You may then experience a shorter luteal phase (thickening of the uterine walls), which could result in premenstrual spotting. A luteal phase shorter then 12 days can be a cause for concern for some women. Charting your basal body temperature is the best way to determine how long your luteal phase is.
Most menstrual cycles are an average of 28 days. If your cycle is short, it could indicate the quality of the egg is failing. As stated previously, early ovulation, combined with a shortened luteal phase. If your cycles have consistently been 26 days and regular there might not be a cause for concern.
Pinpointing dates and timing are as pre mentioned the best and least expensive way of determining any issues. If you do have any concerns, seek your doctor’s advice.