Is Ml Enlarged Spleen Causing The Pain On My Left Side Under The Rib?

Hi , I am 45 year old female. I had gallbladder surgery last april. I have thalassemia minor and also have an iron deficiency. I have Hashimoto (thyroid problems) but do not take any medication. In the last couple of months I have pain on my left side under rib daily. Not all day, but a good part of the day. My thyroid doctor mentioned that my spleen is enlarged due to thalassemia. I had an MRI before gallbladder surgery and that s when my enlarged spleen was detected. I am worried about this pain on my left side. Is my spleen causing this pain and is it serious? Thank you, Mary