Joanna, can you post a picture of the eggs? I really doubt they'd be Monarch eggs this late in the year. Plenty of other things lay eggs on milkweed. This has been a banner year for Large Milkweed beetles.
"My work is loving the world. Here the sunflowers, there the hummingbird — equal seekers of sweetness. Here the clam deep in the speckled sand. Are my boots old? Is my coat torn? Am I no longer young, and still not half-perfect? Let me keep my mind on what matters, which is my work which is mostly standing still and learning to be astonished." — Mary Oliver, from Messenger