No,
@DavidTree.
In Luke 21:36 we are told to pray that we may be accounted worthy to escape
those things which are going to come upon the earth.
It is therefore not a sin to pray for the same and to believe that Jesus is going to answer that prayer on your behalf.
If you want to continue to believe in a post-trib rapture, or even mid-trib/pre-wrath, it's alright...
We'll explain it to you on the way up.