Period 5 days late had intercourse day before period was due woke up today with bleeding dark red to lightish pink could this be implanration bleeding?

Implantation ?: Implantation bleeding is light, and occurs generally four to five days after ovulation which in a 28-34 day cycle would be well prior to "five days after your period was due". Obtain a serum HCG test to be certain about pregnancy, and if positive, see your OB physician, as a pregnancy can occur outside the uterus (ectopic) which needs immediate attention.