Had 2 unopened packs then went to open them. Opened first pack ok, then during opening pack 2 i got disconected from game. Comming back to the game i had my Cards from the first pack, but no Cards from the second pack, no unopened pack, the second pack just disapeared out of thin air…
Hey there Darkleader2,
Sorry to hear that you were robbed of the oh-so-satisfying moment of opening your packs in Hearthstone by a pesky disconnect!
As it says in our support article below, Hearthstone Cards are never lost due to a crash or disconnect, even if you don’t see what they are, as the cards you get are generated instantly the moment you confirm you watn to open them!
You should find some new cards (Or perhaps some duplicates?) in your collection already 
Hearthstone Packs Missing After Crash: https://battle.net/support/article/10375