In IVF, HCG is absent in the uterus because the embryos are in a dish, not in the fallopian tube triggering HCG production. Placing HCG into the endometrium improves its “readiness” for transfer. This helps with implantation and is done the day before the transfer (or Saturday if your transfer falls on a Monday).  It is your responsibility to bring the HCG with you to this appointment.  Charges will apply for this procedure.