Picture Of Implantation Bleeding Old Implantation Bleeding?

Old implantation bleeding? - picture of implantation bleeding

Two days ago, I once saw (dark pink) when they are dried. I have 5 weeks and is based half of the pregnancy on my period. I panicked and went to the doctor yesterday and they have a vaginal ultrasound measured me at 6 weeks, with some alarm that the doctor thought it was a breeze, but could not say with certainty, because it was small and Photo has been crystallized. Anyway, we only have my blood HCG test to ensure that they grow. I was relieved after the ultrasound image, but I wonder what the situation because they have sex. The doctor said it could be the implantation of the placenta, but I thought it would happen about 3 to 4 weeks ... not 5 years. Is it possible that the implantation bleeding occurred, but now is out? I had no other place.