I'm not a breast cancer survivor but wanted to chime in with some solidarity! Congrats on getting through the evil C and the evil treatment!! I had lymphoma as a child, 2 years of chemo etc, and still don't really know how it's affected me long-term: I'm worried about early menopause and long-term fertility (I'm 32). I had a super-healthy pregnancy and ds is as healthy as can be, so no problems there.
There's a "cancer survivors" tribe over in Finding Your Tribe, I believe, so you might find more resources with those strong mamas. It's astonishing and annoying how little actual research there is on this. Good luck--I'm sure you and your little one will be fine.