Steemit rewards disappearing.

I've seen several of my rewards disappearing after the 7 days waiting period and haven't found anything in my wallet. And can't find the arrow to check the payouts of the posts either. I watched one 0.02$ reward reach the time limit and it stated 0.02$ received 1 minute ago and soon after it disappeared, so I think it can't be because of the deprecation of the reward itself. The amounts have been small 0.01$ or 0.02$, but I was hoping to slowly build my account with these small rewards.
I've received only one curation and no author rewards since I started my account.

I'm fairly new here and don't know what's behind it, is there some sort of minimum payout I haven't reached or is it something else?

Could someone enlighten me a bit, please?