I bf'd my son though pregnancy and recently just weaned him a few weeks ago. He still nursed a few times a day and a couple times during the night. I think the around the clock nursing really helped my supply stay the same. I also made sure to drink mother's milk tea and ate oatmeal once per day.
I noticed some sensitivity and pain, it would come and go. I just roughed it out, didn't give up because of the pain. Went on as normal as much as possible.
I got to say, tandem nursing once babe was here was a God send! When I felt engorged DS1 really helped me out.
Good luck, I hope you are able to keep your supply! I am going to TTC #3 when DS2 turns 1 so I am hoping it works out just as well as the first time.