Welcome to HCM. I read your question carefully and I understand your concern. From the information you gave, the first thing I suspect is muscle strain. The suspicion for this condition is even higher after you have done examination, even a CT scan. Regarding the Amoxicilin therapy, it is an antibiotic and I can t find a reason for taking that, but for sure the doctor that prescribed it had a reason for that. I do have some questions though. Is the pain localized in you abdomen or between the lower ribs in your right side. The pain is steady or it begins or worsens with movemens? Do you have any swelling or bruising? Is it tender when you touch it? If it is more localized between your ribs, it gets worse with movements or sneezing or deep breathing, it might be tender when you touch it than probably it is just muscle strain (as I said you excluded major conditions with examination. Beside this, the condition how it started (stretching to much to get something) and an acute onset, all lead to muscle strain. In general, muscle sprain can be treated with RICE therapy - rest, Ice application, Compress and Exercise. To alleviate the pain you could take pain medication like ibuprofen or naproxen. It is necessary to limit the movement of the torso (rest, but just the firs days). Gentle stretching exercises can help strenthen the muscles. Pain can be alleviated applying an ice pack for 15-20 minutes 2-3 times a day (ice should not be in direct contact with the skin). For a full recovery it can take 4-6 weeks. Feel free for additional questions. I hope the answer helped you. Best regards