I think I nose piercing might be infected idk what to do

 OK so I got my nose piercing when I was 15 and now I’m 21. I’ve always had a stud but yesterday I decided to switch to a hoop my stud size before was 20 G and the hoop I recently got put in Is 18 G. When he put in the new hoop it really hurt and afterwords it hurt as well but the pain went away and now it’s just sore and red. Ever since then it’s been pussing like white yellowish green pus. I’ve been cleaning it but I’m trying to figure out if it’s infected or healing . Plz help so I can see if I need to get it checked out