Definitely do not dig them up, this could harm them beyond help. 6 days is a long time, but not unusual, be patient and don't keep them too wet or cover them with the lid. Seeds need access to oxygen to aid in growth and they also don't need excess humidity to sprout, just moist conditions. If they have been too wet and under the lid, this may have unfortunately caused the seeds to rot from not being able to "breathe". Hopefully not, but possibly. As The8thChevron said, you are much better off starting your seeds in the moist, not wet, peat plugs, rather than fiddling around transferring the fragile sprouts between containers when they are at their most vulnerable stage. Plus the roots will start growing downwards immediately, not growing sideways as when in paper towel, which just uses up precious energy when the root then has to change direction from sideways back to the normal direction of straight down.
Remember, moist, not wet and seeds need to breathe air. Hope this helps,.... Organoman.