I found the problem, guys.

The network is overloaded, about 250 transations in the unconfirmed pool.
I found 2-3 blocks in latest transes, so we need 90-120 blocks in best case to get trans included into block and 40 more for bittrex confirmation.
Guess it will start from 10 hours.
While rate is going up network activity will just increase.

I sent my second trans 6 hours ago, about 100 blocks already mined but my trans still in mempool, not included in a block.
First one was lucky and needed about 15 blocks to inclususion.