Quoted from user "franky1" in this post:
https://bitcointalk.org/index.php?topic=5081853.msg48528029#msg48528029blockchain rules are not 1 block every 10 minutes
its 2016 blocks every 2 weeks. coded
which only in the human brain but not in code calculates to AVERAGE 1 block ~10min
this means there are times a block can arrive in 2 minutes and another block can arrive in 18 minutes and on average thats 2 blocks in 20minutes thus still being ~10mins each
in the last 24 hours ~144 blocks should have been produced.
24 hours ago block 552871 was made
at time of posting 552994
123 block mined
=5.125 blocks an hour = less than 12minute average
if you check th other blocks before 552994(current block at time of this post)
552994 51 minutes ago
552993 1 hour 2 minutes ago (11 minutes before ..994)
552992 1 hour 6 minutes ago (4 minutes before ..993)
552991 1 hour 16 minutes ago (10 minutes before ..992)
so ask yourself before panicing.. why were you not screaming celebrations of the 4minute block?
infact lets look at a few more blocks. knowing 6 blocks are average an hour... yet an hour before ..94
552994 2018-12-08 06:50:47
552984 2018-12-08 05:50:52
means 10 blocks were made in an hour. thus the previous hour before ..94 blocks were being made in ~ 6 minutes
So yeah, it's kinda normal.
I have a 20 sat/b transaction also waiting to be confirmed. Just wait it out, when the blocks are found faster, the fees will drop and it will get confirmed.