I have gained 9 pounds at 26 weeks and belly measuring 2 weeks behind

My doctor said after observing me that she would be so surprised if the baby weighed 7 pounds. My stomach is measuring 2 weeks behind and I have gained 9 pounds. I read that your weight gain can influence babies. Is my baby going to be unhealthy?! She said we would just monitor him. I am 5’8 and started pregnancy at 140 and I am now at 149. Any reason to be concerned?

Edit: I do eat very healthy. I definitely don’t deprive myself.