After my first, I took the mini-pill and spotted for an entire month. So, I gave up on them (relying on withdrawal...yeah, I know...but we knew we wanted more children, so if it happened, it happened). Now that I've had my third, I have an IUD. It's recent, but my first period since wasn't the horrible cramping mess I was prepared for (I have a copper IUD).
Also, I know a lot of people believe that you may not be fertile b/c of breastfeeding. But I've exclusively BF all 3 of my girls and I've started my period at 6, then 4, and now 2 months post-partum.
I'd get an IUD over again in a heartbeat. I'm irregular enough as it is...I hated the random spotting that happened with the pill.