Not gaining weight

lzygrl42

So before I found out I was pregnant at 5 weeks, I weighed 132lbs..I am now 13 weeks and only gained 1 lb. i had bad M/S all day up until a week or two ago. My appetite is back but today I have some kind of stomach bug which has been causing a lot of diarrhea.I now am back to 132.4 lbs..I am getting concerned that baby is being malnourished and that I am not gaining any weight at all..My mom said when she was pregnant with me and my sister (twins) She only gained 13lbs and with my older sister maybe around 15lbs..am I being too nervous about this? Don't go back to OB until March 1st.