"unpleasant thought" is correct and usable in written English.
You can use it when you want to describe a thought that is troubling, uncomfortable, or worrisome. For example: "I had an unpleasant thought that I might have left the oven on before I left for work."
Before I started to meditate, I thought I was failing every time I had an unpleasant thought, be it unhappiness, loneliness, anger, anxiety, or frustration.
"That is an unpleasant thought for most people".
A pound to a penny, if you're a non-Muslim, the same unpleasant thought fleetingly crossed your mind as it did mine: "Oh, they do look quite like..
THROW THEM ALL OUT Another unpleasant thought nagging at Republicans is that more of their own incumbents than believed could be at risk from voters eager to toss out established politicians of both parties, not just majority Democrats.
Others will wonder what ails publishing that it nurtured and rewarded a clear fantasist for so long; while the unpleasant thought might dawn on other segments of the media that they too could be similarly vulnerable.
An unpleasant thought follows: that maybe the only thing that could relieve our national anxieties is something bad happening to us — something so clarifyingly awful that we're forced to become solemn and still and agree about it.
There are times, of course, when unpleasant thoughts are the most useful thoughts.
The monarch gives not one flick of its gaudy wings for such unpleasant thoughts.
If this isn't protracted war, what is? Unpleasant thoughts on a lovely, starry night.
Nowadays, you have to slap harder: As I stood before the old man's coffin, unpleasant thoughts came to me.
Perhaps a day off and the return home to their fans will help clear the Cardinals' heads of unpleasant thoughts.
