I'd be in pain from SPD. Definitely selfish for not wanting to go through some pain for another bub.
Nope definitely not selfish. I can't think of any other human endeavours where people would willingly put themselves through months of agony.

I agree wholeheartedly with Gracious Goddess. You have to find your own place of peace with your decision and it matters to no one except yourself and your DH (weighted towards yourself ).