Wow, I thought I was the only one! I have a daugther 3, and a son 1, and had big complications with two c-sections. Initially I was planning on a natural birth, but my daughter was breech, thus the first c-section, which also meant having a second one with my son. The complications from my first left me with a lot of scar tissue and other things, which caused more complications with my second c-section. So even though I never planned on going the c-section route in the first place, sometimes you have to play the hand you're dealt.
My doctor has told me that any future kids would mean a highly risky delivery and probably additional surgeries to put everything back together after the delivery. So after a lot of consideration, my husband and I have decided not to have a third child.
I have two pieces of advice for you:
1) If your fear is only for a long pregnancy and dealing with temporary issues like anemia that will pass, then I say "go for it!" Would you trade a lifetime with another child just so you didn't have to have 9 miserable months? Believe me, I know it's not fun, but the issues are temporary, and at the end of it all you'll have another beautiful child.
2) If however, your fears are for more permanent damage being done to you or the baby, then I say be grateful for what you have. That's what I've learned to live with. Even though my body has this limitation, and it's not what I planned, I am healthy and I have two beautiful children who are the love of my life. Every now and then when I see people with three kids, my heart still aches for the third child we won't have, but then I look at the two I do have and remind myself of how lucky I am to at least have them. I've had several friends who couldn't have any, so I know I am very blessed. And as a friend of mine says, 'if you've got two kids you like, quit while you're ahead."
Hope this helps a little. Good luck with your decision!