Nose piercing replaced with earring that keeps falling out. Help?

I got a nose piercing last week. It fell out and I couldn't find it so I quickly put a earring stud in it. About a week has passed but this earring stud keeps coming out. I don't think it's a good idea to fiddle with it but, as I have to fiddle with it when it falls out anyways, and I'm afraid of it falling out and me not realizing it, I don't know what else to do. My mom surprised me with some surgical steel screw studs but they are a lot skinnier than both the original piercing that came out to begin with and the stud earring that I replaced it with. I've researched and know that you aren't supposed to change the piercing but it's going to fall out one time without me noticing in which case I will need to put a replacing piercing in anyways. I want to avoid an infection but I do NOT want to get it re-pierced. I fainted twice from the site of the blood and the pain... I know about care and such (cleaning with soap and water, neosporin, salt soaking), so I guess my biggest concern is the size of the new screw piercings. If it's smaller will the hole heal wrong? Thanks for your help!!