Is it normal to still have joint pain 2 weeks after an iron infusion?

Not surprising: I certainly would not consider a joint effusion two weeks after an iron infusion normal, but it is not unheard of nor is it surprising. If there is some underlying reason for inflammation in the knee, such as a meniscal tear or arthritis, the iron infusion can exacerbate the pre-existing inflammation in the knee. This will cause the infusion to stick around longer. If you have other symptoms, i may seek further advice from orthopod. May need joint drained and fluid sent for analysis.