Hi Baladay - I am in the exact same position as you. DD will be just over 6 months when I go back to work, and I too have been EBF up until this point. I had thought that I wanted to stop BF-ing totally when i went back, but am now thinking I want to still BF before and after work, like you.
Anyway, my friends with babies have advised to get a bottle going for the 11am and 3pm feeds, not only because it'll be hard for DD to be away from me at nursery, but to have to do the bottle for the first time at the same time might be a lot for her to deal with (and introducing solids at the same time!) Moreover I think it's better for you to get your boobs used to not feeding during the day, or else you'll suffer from engorgement and possible mastitis which is nasty.
I sit here saying all this whilst DD looks at me in disgust as I have tried to give her her 11am bottle. She just hates it. I started to drop the 11am boob feed onto bottle on Saturday just gone, and so far, she has managed to just not feed at that time for the past 2 days (looks like 3 at this rate!) and instead preferring to go hungry until her 3pm boob feed. Which is all fine by the looks of it (damn she's stubborn!) but from this coming Saturday, I will be dropping the 3pm boob feed onto bottle as well, so she really will have to meet me half way or else she won't be eating anything after her 7am feed until her 7pm feed!
I think I'm going to start introducing solids a bit earlier than normal, say from next week when she will be 21 weeks, just so she is getting some extra calories in, in case this hunger strike continues!
Good luck, whatever you decide to do.
x