It's either an allergic reaction or the posts are too thick or too tight causing too much pressure on your earlobes. Please remove and let it recover first and then I would suggest a visit to your nearest store if possible. My SAs (Cartier/ VCA) have always identified the problems and solved them for me.
I agree with this! I also have the Love studs (two singles) and have zero issues. I have worn them with both the original screw ball backings, as well as the butterfly backings that I had them changed to. No issues with either.
You could also try cleaning your earrings. Maybe something is on them that is bothering you.
Hope you can figure it out!