His side's 3-1 defeat to Birmingham on Saturday leaves them without a league win in eight matches.
Clough's side have dropped to 15th in the standings and the gap between Derby and the relegation places is down to just six points.
The Derby boss believes his team need another three wins from their remaining nine games to steer clear of trouble.
And voicing his concerns after the loss at St Andrew's, he said: "We have been looking over our shoulder for a while, don't worry about that. We have not been looking up too often.
"We have always had one eye on it because in the Championship when you get a few injuries and get on a bad run, it is very difficult.
"Every team is vulnerable until you get to that 50-odd points mark. We have known that for a few weeks and that is why we have been absolutely desperate to reach that mark.
"There is certainly work to be done. We have nine games to achieve it. We need another three wins or something like that but we think we will get them."