implantation bleeding?

okay ladies, I'm freaking out! my ovulation just ended on the 22nd, I'm 8 days away from my period and when I just used the restroom, I had a very light amount of blood after wiping. I put on a liner just in case, but since it's only 4 days later, do you think implantation bleeding may have taken place? I've had three children previously (all boys) my hubby and I are TTC for a girl but we will be happy with whatever we have. I've never ever notice blood before, but all three of my boys were..."surprises" lol this is our only ever planned baby. What do you guys think? Do you believe in implantation bleeding?