I pierced my bellybutton and it's starting to look a little irritated can i use mupirocin ointment 2% on it?

Yes: however, need to watch it closely and if redness extends despite topical antibiotic, would recommend eval by physician. Could be more severe infection in that case and there would be risk for sepsis, heart infection, etc. if fever, chills, gen aches, enlarged lymph nodes; then go to ED. infected naval piercings can take up to a year to heal. metal sensitivity also possible