Total newbie: Where is my half ethereum gone?

Hi all,

at the end of 2017 I was testing out ETH mining. I read a tutorial, opened a wallet at MEW, joined a pool (ethermine) and let my PC mine for a few weeks or so. In this time I was collecting half an ETH, I think. I am positive that there was some value >0 somewhere. I say „somewhere“ because I wouldn‘t swear that I saw positive balance in my MEW. Perhaps I only saw the balance in my geth account.

However, both the MEW as well as the geth account now show a balance of 0. I also can‘t see any transaction that ever happened.

I hope you can help me to understand why everything looks as if I didn‘t do anything besides setting up the wallet and the geth account. I would expect to at least see any trace of my mining. But perhaps you can tell me why there is none or how I can find the traces. Perhaps data is deleted after some time? Perhaps the pool kept my mining earnings because there was never a payout? I really would like to be able to see where it went. It wasn’t much in any case but I’d like to know what happened.

Thanks for any replies!