Hi there,
When the doctors place the embryo(S) in the uterus they do not implant it. It will take a week to a few days to implant on its own (depending on whether you have a two - three day transfer or a blastocyst transfer ). In the time that the embryo(s) is developing further ready for implantation, they can wander off into the fallopian tubes - as they can actually move. Simple as that!
Just to reassure you - it is rare that this happens and most of the time the embryos stay in the uterus.
Bekki
Me 32 DH 35
TTc since 2000
Feb 2005 - ectopic pregnancy (NOT related to IVF) - left tube burst and was removed.
October 2006 - 1st IVF 0 BFN

November 2006 - natural pregnancy - expecting Aug 12th 2007.
