Hello, Actually I hope I can allow you to understand, that argus are reptiles, and reptiles are ectotherms. Which means, they raise and lower their metabolism using external conditions.
Even more, they are dependant on external conditions for all of their needs, food, energy, moisture, security(peace of mind), etc.
Which means, please follow me, You should not expect anything from reptiles. Its your input that allow them to succeed.
They can reproduce, in under six months of age or they may never produce, it depends on conditions, and in captivity, your conditions, and your continued applied conditions. Which means, if you let up and are incosistant, they will respond with the same.
Ok, thats over.
For us, argus females will lay eggs anywhere from 18 inches TL(have one gravid now) to the lenght of yours, 30 inchesTL.
Normally if you have a female and it grows over 30 inches, and shows no sign of cycling, getting fat, then losing it, doing it over and over, Big changes in feeding pattern or drops infertile eggs, then you most likely have a male.
If you posted pic. Some of us could give a guess, but thats only accurate if your monitor displays real defined sexual characteristics and if it did, you most likely wouldn't be asking that question. Good Luck FR