Revenue Income all gone???

I started posting my comic here in Feburary. And after a while posting I was able to get a tiny amount of earings. A couple of months past and today when I check again, it says my comfirmed income is 0. I have never made a payout yet and I clearly rememebr having earned a couple of dollars in my revenue before, how come they are gone? I really need help on this! Thank you!