Are you talking about an ectopic pregnancy--where the egg has implanted anywhere besides the uterus?
1 in a million. Seriously.
I had an ectopic pregnancy back in August of 07. We ended up having to terminate the pregnancy because I was at risk of rupturing. I've read of only one person who ever survived an ectopic pregnancy through to term--and her egg was implanted in the ovary, not the actual tube, where mine was.
at 12:16 PM on Jul. 10, 2008