Anywhere that hurts in your body where there is an organ, is really cause for medical attention.
That's kind of my rule of thumb. If it were my knee I could probably wait it out, but if its anywhere there is an organ in my body, I go to the Dr., and I dont have insurance I just have to go and pay, and I dont know where you live, but if your here in the states there are those little clinics now in all walgreens, cvs pharmicies etc, and several urgent care places that range between 60-100 for the visit and of course meds etc. would be extra but if your hurting where theres an organ and you are making a big change in your life, like you, are that can really affect you physically... I would scrape up the $ and go, even just for peice of mind.
When your attempting to get sober any added stress, I noticed for me, was always a great excuse for me to go back to my old ways.
Please see a Dr. so that doesnt happen to you
<3 Dream