Is there not already a thread for pack openings? Congratz on your nice pack. However, I've seen better ones. Even once where someone got double gold legendary. Unfortunately that never happened to me though :/
I recently opened some packs of GvG because, back in days when I started, the legendary in the first 10 packs wasn't guaranteed. If you never ever found a legendary in GvG, TGT and other wild sets, I suggest you to open some packs, you should recive your guaranteed legendary in the first 10 packs.
Edit: I also got two nongolden legendaries twice and several golden legendaries (like 6 or 7) but never in the same pack before. Playing since TGT (september 2015).
Since i love probability and if there is 1% chance for a card beeing legendary and 0.1% for a golden legendary (that's what statistics roughly imply) chances for 2 or more regular legendaries in 1 pack are 1-(0.99^5)-(5*0.01*0.99^4) ≈ 0.1% , 1 out of 1000 packs.
Chances for 2 or more golden legendaries in 1 pack are ≈ 0.001% , 1 out of 100000 packs, go play lottery the same day.