It's possible it's joint pains from humira and it's possible it isn't from humira at all.
Joint aches are more common with biologics when we have developed antibodies to them. You can ask your gasteroenterologist for an antibody test for humira, i know Prometheus labs offers a test for it: Anser ADA bloodtest. /www.prometheuslabs.com/Products/Default.aspx
We can get joint pains unrelated to our meds as a extra intestinal manifestation of our UC. The ccfa has a good fact sheet on it: www.crohnscolitisfoundation.org/assets/pdfs/arthritiscomplications.pdf