Pre Seed


We are TTC now for about 4 months. I have a history of an Etopic pregnancy and was told it will be harder to conceive naturally. We have decided to give Pre Seed a try as I am not ready to give up Naturally... I am currently in my fertile window and ovulate on 12/28. When should we use Pre Seed? My window started yestersay and we've had sex twice but with no lube. ????? Help, please! I will want this to be my time and hope the pre seed helps.