Human embryo implantation timing Human blastocysts should hatch and begin to implant 1-2 days following the day 5 IVF blastocyst transfer. The blastocyst should hatch and implant at the same time in a natural setting (not IVF), roughly 6 to 10 days after ovulation. In an IVF cycle, most embryos will not develop past the early stage of development before being discarded, so only one or two embryos should be transferred at a time. It is normal for some embryos to remain unfertilized during IVF treatment - this is called "polyploidy" and most of these cells will degenerate before birth. The truth is that there are no strict rules about when implantation can occur after egg collection and embryo transfer. It is very common for it to happen on the same day, but it can also be several days later. Some women may even go through menopause before finally losing their pregnancy rights to over 100,000 women in America alone. The only way to know for sure when your embryo has implanted itself into your uterus is through a blood test called hCG which we will discuss below. So, implantation can happen on the same day as embryo transfer or several days later. Just make sure you let your doctor know if you plan on becoming pregnant right away because there are certain treatments such as chemotherapy and immunotherapy that should be avoided during pregnancy.