Could I be pregnant? I had my period on the 27 of march 2015 and had sex on the 02 of April and on the 06of April I saw a little blood spot on tissue

Implantation. usually occurs 6 days after fertilization of the egg. The egg is fertilized while it is in the fallopian tube and over the following 6 days, the developing zygote travels down into the uterus where it implants into the built up tissue lining the uterus. The slight disruption of the blood rich uterine lining can cause passage of a few spots of blood, usually seen on toilet tissue after wiping.