pain right below sternum by ribs.

Trisha
Hello, was hoping someone could help me I have pain under my sternum right in the center of my upper stomach like between my ribs. Sometimes it throbs and other times it feels like it is pinching. I was seeing a chiro because I thought it was my ribs but now I'm not so sure because nothing has changed. Searching online people said it could be muscles or just stretching of my insides. 
Has anyone else had this issue? Can you help?? I am 23 weeks pregnant.