Compliment of the season doctors! how early can fertilization of egg and sperm occur post ovulation ?

mature eggs can be fertilized once released for 48-72 hours, and exposure to adequate sperm can occur even if sperm is available 24-48 hours prior to release of a mature egg. Once ovulation occurs, it is the capacity of the egg which determines whether successful fertilization occurs.

Once a viable ovum is released from the ovary it can be fertilized where ever the sperm reaches it. It migrates fairly swiftly to the falopian tubule, and at any point in this journey union of sperm and egg can occur. I hope this puts things into perspective.