If you go to the PAYOUTS page in your account, it will show you exactly for which Mining Day each payment is. The payment for Mining Day 20.02.2015 has gone out now. It may be showing twice, but that's a display issue only. Your wallet won't receive it twice

Payout for Mining Day 21.02.2015 will follow shortly, or just about now.

It's not a combined payment so you can keep track of which Mining Day was paid out and which wasn't (yet).