My manager has asked me to go into work next Friday afternoon for a few hours, I don't mind (will be quite nice actually I left really early lol) but it is going to be at quite the expense for me because I will have to pay to commute there and try and get childcare for DS. I am still in the "full pay" aspect of my mat leave, will I get paid for the extra hours or will I basically be doing it at my own expense?