string input3 = "26. AUG\r\n2014\r\n27.08 Testing 1\r\n -100\r\n20. AUG\r\n2014\r\n27.08 Testing 2\r\n -90\r\n15. AUG\r\n2014\r\n27.08 Testing 3\r\n 200\r\n9. AUG\r\n2014\r\n27.08 Testing 4\r\n 50\r\n4. AUG\r\n2014\r\n27.08 Testing 5\r\n -200\r\n25. JUL\r\n2014\r\n27.08 Testing 5\r\n -200\r\n";

string pattern3 = @"(?:[^\\]+\\r\\n){4}";
var matches3 = Regex.Matches(input3, pattern3);