I am experiencing side pain below my ribs on the left and right side, more so the left. i also had a hysterectomy almost 2 weeks ago.

Postoperative pain: Can be a variety of reasons - from the less serious such as muscular through to the serious such as postoperative pulmonary embolus or postoperative urinary tract infection among others. Needs urgent assessment. Recommend urgent consultation with a doctor licensed in your area as may need examination and tests (urine, blood, possibly X-rays or scans) to sort this out.

Atelectasis?: My assumption here would be something called atelectasis, a lung condition which is temporary and which tends to occur after abdominal operations. Essentially, if it hurts to take a deep breath you tend to take shallow breaths which leads to compression of the lungs which can be painful. A chest x-ray would show it. But this is just an assumption, sight unseen of course.