Being diagnosed with PCOS, charting can help in other ways. Charting can show you if your temps are in the average range. If you have higher or lower than average temps during your cycle it can indicate thyroid disorders. Charting can show you if you have a long enough luteal phase. Charting can show if your progesterone levels are acting properly during your luteal phase.
Progesterone is a key ingredient in early pregnancy.
Your luteal phase, according to what I've seen and read, is consistent month to month no matter if you ovulate early or late. You can plan things a little better. I know, it sounds so cold and clinical. If you're not careful, it can take all the fun out of being together. You're both in this together.