Baby growth slowed down at 30 weeks

Natalie
So I went to doctor today and my baby has slowed down on his growth. At 28 weeks he was ahead on his weight average at 2.5 pounds and now I went in at 30 weeks 5 days and he's only 3 pounds. Doctor commented on it, but didn't seem too concerned. He said we will see where he's at in two weeks. I'm just worried I'm doing something wrong. I eat healthy and take my vitamins everyday. Any ideas or suggestions? Anybody have a similar situation?