Humira

No official diagnosis, not looking for diagnoses. My rheumatologist believes I do have PsA, however, wanted me to do an xray of SI joints (showed nothing) and now is scheduling for an MRI. My biggest issues is my hips. They’ve always been stiff on the morning, but now it’s becoming unbearable pain. My feet ache too first thing in the AM. The only tests that come back with something is ESR of 42 and elevated CRP. We discussed humira as a future option. I’m scared my MRI won’t show nothing and I’ll be in limbo. Has anyone ever been able to do a trial of humira without an official diagnosis?