Work and breastfeeding

I'll go back to work when my LO is 4mo. I'm currently exclusively breastfeeding but baby is feeding 7-8 times during "work hours". My nursery allows me to go there during the day to breastfeed but I can't go there 8 times / day obviously (or I would never work...) How many times should I go there? How many times should I pump? When should I pump? If I start work at 8am, should I breastfeed AND pump before going to work?! Thank you all for your help / advice /... =)