It sono should be able to tell you

yeah, usually they can guesstimate by measurement of your uterus by feel during exam and last period date or hcg levels in blood work, but an ultrasound will give them a more accurate date. they initially said I measured 10-12 weeks by physical exam, and LMP date would have put me at 18weeks. I had my ultrasound a week later and little one was right on track for 19 weeks. I was just measuring small at the time for whatever reason. I've also been told that the measurement by feel isn't the most accurate either. im still measuring a little on the small side, but ultrasounds show little man is right on track where he should be.

it was a family doctor but I had blood work done and she said that it looked in the 4 or 5 week range but wasn't sure I go for my first ultra sound on the 26th to see for sure I think

I don't think anyone can tell you that by a belly photo, and a Dr not knowing that is odd, doctor's should be able to tell you, blood work, scan, idk what kind of doctor said that to you, seems weird.