It's natural but not bad. One thing we can't forget is that change manifests in our body before anything. Which is why our body is the center of a lot of insecurities and anxiety. Which is why it is really important to know what to expect from your body. Always ask your gynaecologist or midwife about how pregnancy would look for you. The "pretty perfect" people on social media are far from real. Your body image is not based on the anxiety you feel or how you looked before you were pregnant. It's linked with your perception. So that's something you could work on. You can also do activities like yoga, journaling etc. Just know that no matter what, you assuming the worst about your body is not going to help.