How Can A Hard Abdominal Mass Be Treated?

Hello there. I just notice an abdominal mass in my lower abdomen about 3 weeks ago. I waited to see if it was possibley a bowel movement or if it would go away, however it has not. The mass if very hard, fixed, and non-tender. I am a 27 year old female, and I have one 6 year old son. Wondering if you could shed some light on this. Thank you.