I made a point to check my chart while I was at the midwife's office today. I am 18 weeks and have gained 6 pounds. I'm not worried and my MW hasn't said anything to me, either. When I was pregnant with my second DD, I was seeing an OB who was constantly on me about my weight. In fact, at one appt, he said I MUST gain some weight by my next appt... at that pt I was about 24 weeks and hadn't gained anything. At my next appt, I had lost 2 lbs. The OB accused me of not eating, of starving my baby. Then, he sent me with the nurse to the lab and cornered my husband, asking him if I was really eating or not. I'm embarrassed to admit that I continued seeing that jerk until I found out his call policy and that he had already decided just to induce me for his scheduling convenience, when I was 37 weeks. I told him I couldn't agree to that, and he ACTUALLY said, "Good luck finding someone to take you now!" OMGoodness. But I'm so glad that all happened, because that's how I found the MW group I'm with now. They took me. LOL
ANYWAY, sorry to run off topic, but no worries. If you and baby are growing as you should, don't mind the scale! ;)
ETA: I was 37 weeks when I found out his policy, not that he wanted to induce me at 37 weeks.