Birth control while breastfeeding?

Curious what you guys are on/doing for birth control. I plan on breastfeeding but do not want to count on that as my birth control. 
I can't have an IUD due to the position of my cervix, and condoms failed my husband and I after our first so we are going to have Irish twins any day now lol!
My body definitely needs a break from being pregnant back-to-back. I plan on discussing this all with my doctor, but figured it wouldn't hurt to know a little a bit first. 
What birth control are you on? Is it safe while breastfeeding? And how effective is it?