Have you or do you know someone who has gotten pregnant while using an IUD?

I'm due to have my second baby in 3 weeks and this is the type of birth control I am interested in because I am horrible at remembering pills and stuff. I have heard of a couple woman actually getting pregnant while on the IUD and I know it is possible because no birth control is 100% but I really think this is my best bet. Also are they as affective as the pill? It's either this or my hubby was a vasectomy and he is only 23 and this is only our second baby and I might want a little girl someday! (this will be my second boy)