yes if you ask them they should provide somewhere for you - my work was very accomodating of this, they let me use the health room which also has a change table, bar fridge, bed to lie down on if you want etc. i do work for a big company but it is male dominated and i found they just needed to know what i needed/wanted if you know what i mean. i have heard of other ladies who have had a meeting room (with no windows LOL) booked out for them at the same time every day - i think this works ok too. but if you are that close to home, personally i would pop home, put you rfeet up, have a cuppa and pump away - just make sure they know how long you need and at what time... the relaxed environment will be better anyway.
the aba will def have info on what your rights are if you do need to remind your worksplace but hopefully it wont come to that and needing to be so formal about it.