Personally I kept mine and fitted back into them no worries. But I didn't BF for very long.
Bras are expensive though so I'd keep them at least for a while and see how you go. You can always chuck em later or there's a link somewhere on BB for a charity that you can donate them to.
Even though they will take up space, I would keep them until 6 weeks after you finish breast feeding. You might fit into them. Personally I ended up shrinking smaller than before I was pregnant (doh!) so had to get rid of all mine.
So my advice: pack them away but don't get rid of them yet.
I would keep them. I am usually a B as well and went up to a D while breast feeding but I am back into my old bras once again now I am no longer feeding.
Dee I'd keep them - your breasts may change shape, or in my sad case shrink, but it is better to keep them JIC and not have to spend all of that money again. I packed all of mine away with my pre-pg clothes so they weren't even there for me to miss not wearing.
I've kept mine, I was a C pre pregnancy and now a D, I've been either pregnant or breastfeeding (or both!) since July 2006 so haven't actually worn them yet again
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