I sent 4 boxes out at the same time all via Priority Mail and normally I'd get a confirmation # for each package but this time I didn't

. 3 of the 4 boxes were delivered within days from the day I mailed them and the fourth one is still missing and it's been about 3 weeks. I've sent hundreds of packages and have never had a problem. Anyone else ever send a package and it take several weeks? I'm hopeful it gets to it's destination and that the person I sent it to is not lying since I didn't attach a confirmation #.