L.M.
Not with just one measurement I wouldn't, at least not until you get results of ultrasound. I measured right on target with my son the whole time but one midwife insisted I was "awful small" to be as far along as I was. I was 19 so I think she was trying to scare me. Pre-pregnancy I was 94 pounds...had a 8 lb baby. With my daughter, they were concerned about her growth because of one of my measurements but she was perfectly fine and healthy...6lb 10 oz. Don't stress!