So I was in the fest zone and I stumbled upon a Cecropia Lunemara, I used three traps and I managed to catch it but now the pet is nowhere to be found. Ive checked all my tabs and even my hatchery just to see and its disappeared. I know for a fact I caught it though because it even stated that I had caught it. What do I do?

glancing at advanced search, it does not appear that you did succeed. Are you sure it said you caught it and gave you the link to its pet page, and it wasn't telling you that your attempts to catch it scared it and caused it to flee?

Yes, I'm certain it said that I caught it.

well, It certainly isn't in your account- the only lunes that show up as being owned by you on a search are a pb toxic cloud and a tagged moonlight magnolia- so I don't know what to tell you. The only way you could evidence having it would be if you'd clicked the link to go to its page and had that up, and it seems you didn't do that? As such, with no evidence of the lune actually having been caught, there's not much that can be done.