Hi my girl is in her twefth day of season and is still showing signs of slight blood speckles not as dark as earlier days. I was told not to mate her until there is no sugn of any blood from the vulvaj, just yellowish discharge? What do u think?

Bitches vary some bleed all the way through and some very little.  I have never found the colour od the discharge at all reliable as an indicator of readiness to mate.

Normally the very hard swelling of the perineal area (between vulva and anus) will subside and the vulva softens when tyheya re ready.  Your best indicator is an expereinced stud dog who will generally know when she is just right.