It worked fine, but if I hadn't lost as expected I would have modified my cals. When I was logging I got all of my meat from a farm that didn't have fat percentages or cals or anything (and I rarely eat boneless, skinless chicken breast), so I guessed based on the various USDA options. That's how we deal with the fact logging may not be perfect or our TDEE estimates may be off or whatnot. If you aren't losing as much as expected (or are losing more), you can adjust overall cals to respond to that. More important, if chicken breast is something you have a lot, be consistent.

If chicken breast is not something you have a lot, 30 cal does not matter. and nutritional contents for Chicken Breast and over 2,000,000 other foods at MyFitnessPal. (I would suspect that's the case for chicken breast claiming to be only 94 cal and 20 g protein at 100 g.) It is a good source of phosphorus providing 125 mg or 10 DV. It is also an excellent source of vitamin B6 providing 0.5mg or 29 of the DV. The reason is that some packaged chicken may be pumped up with a saline solution. A chicken wing is an excellent source of selenium providing 21.7 mcg or 39 of the daily value (DV) and niacin, providing 5.4 mg or 34 of the DV. However, if you have packaging information for the chicken breast (which is normally raw unless it specifies), then I would go with it. I would recommend exactly what kshama says above.

Chicken breast calories myfitnesspal