pumping at part time job

Katie
Tomorrow I go back to work part time. I will only be away from my little man on mondays and Thursdays. He currently eats every 2 hours. Do I have to continue to pump exactly at 2 hours or would it hurt to go more like 3-4 at work? Pumping 4 times in my work day just seems like a lot. 
Any other tips for pumping at work?
Thanks!