I fractured a bone in my foot three months ago had an airboot and crutches. Is it normal for it still to be painful at times after walking a good bit?

Yes, this is . Not uncommon. Though on follow up exam mention it to your doctor, somthey can evaluate your healing process.
Not unusual. Foot injuries can take a long time to heal and some discomfort with much activity can persist fora long time (6 months or more). It it is restricting you, consult the person who cared for the injury (or get a second opinion). Many things can influence the outcome.