To solder or not to solder!?

Hey ladies. I'm looking for opinions on soldering your wedding ring and engagement ring together? I do not have mine soldered and have worn them unsoldered for a few years now. I'm thinking of getting it done though because I'm constantly messing with my rings lining them back up because they spin and do not line up, which drives me crazy haha. I'm worried though about getting them soldered. Will it make my ring smaller? Do I need to get them sized up slightly first, because they fit perfectly now. Can rings that have been soldered together be sized later down the road?