It is likely no issue, but pics would help. I've had some ugly eggs that had absolutely no problems. In fact, they molded and had windows, and dimpled weird, etc... Sometimes they just do weirdness.

If the egg box is already sweating a lot (it being only day 4), there might be too much of a temperature swing/fluctuation in your incubator. Sweating tends to happen when there's larger differences in temperatures (when cold meets warm).