Judgmental people

Just a rant! Why do people feel the need to tell you what to do?! My husband and I want to find out the gender of our baby soon, when I'm 15 weeks. We wouldn't find out at the doctor until 20 weeks. My mom and other people want us to wait til we go to the doctor. I've already told my mom that no offense, but she isn't paying for it and it's not her decision. Today she told me I was crazy if I go out of town to a clinic about a hour away for the ultrasound. Really? I just hung up the phone. Why do people act that way to a pregnant hormonal person? Ugh!