Left Sided Pain 36 weeks

I woke up the other morning in severe pain on my left side between my rib and hip and the pain radiates round to my back too. It felt like a severe cramp which intensified and continued for about 5 straight minutes before subsiding. It would keep reoccurring every 15-30 minutes and eventually I went to hospital. The pain was so bad it had my whole body shaking each time it happened, I could barely walk and out pressure on my left side, and I ended up vomiting a few times from pain.

Tests came back clear for kidney stones & it’s not severe constipation. No UTI or other infection found. I was given a lot of painkillers that day from endone to panadeine forte & panadol and nothing got rid of the pain. It can happen when I’m lying completely still or get triggered when I move so I can’t pinpoint what causes it. The pain eventually stopped and so I went home but it’s starting to occur again.

Has anyone else experienced this? Could it just be round ligament pain - but then wouldn’t pain killers help that? 😩