Blue Tit Nestbox Camera

I have a camera in a Blue Tit nest box were I have not seen dad to be for a couple of weeks. I think we have 6 eggs and in the last few days Mum to be has been sitting on the eggs most of the time. Yesterday though one egg appears to have been rejected and looks quite sad. I am also concerned how she will cope with no mate to help feed her and the chicks when they hatch. This is our first nest so finding it all stressful not knowing what is right or wrong.