The Baggies were beaten for the third game in a row on Saturday as they went down 2-0 at home to Norwich City in the Premier League.
West Brom are now in 15th place in the table, two points clear of the relegation zone.
"It's been a difficult week for us. Three defeats in a week is sore, it's painful," Clarke told Sky Sports News.
"It's hard to take but next week we have to go to Cardiff, we have to be resilient and we have to start getting points on the board."
West Brom's record run of consecutive defeats in the league is a total of 11 games dating back to 1995.