Allergic to my rings!
This actually has happened to me with my platinum ring as well. But not when pregnant. I cannot even wear one of them now. Even after a huge cleaning in vinegar, baking soda and boiling water for about thirty minutes, the rash came back. It is only a problem with one of my rings, which was custom made. My engagement ring and it's matching band (which are from a large jeweler and also platinum) do not give me any problems, but my custom one does. I am wondering if there is an alloy or some kind of composite in the metal that has either rubbed away or is newly causing problems. I actually googled this and found that it is really common. Called "wedding ring rash" or something like that. For some people, cleaning it really helped. It didn't for me, though. Try cleaning your ring with the above mentioned solution and see if that helps.
With DS my cartilage earring was bugging me in the 3rd tri. It made a raw spot on the back of my head and I kept scratching it and opening the scab... gross. I kept it in, but finally got rid of it a few months after the baby came. Don't feel like I need an earring there anymore. My rings are white gold. No problems but I almost never wear them since I used to be a lifegaurd and wouldn't wear them to the pool, I'm very out of the habit.
With my first pregnancy one of the ways I knew I was pregnant was due to my belly button ring getting red and sore and bumpy. I went in to the place where I had it pierced and they informed me its not on common for a woman's body when she is pregnant to reject the metal and "push" the ring out and try to close up the whole. That actually got me thinking I might be pregnant and like 2 days later it was confirmed. This time around my belly ring just started to get sore so I took it out before I got the red irritated bumps. With earrings I am having to stay with my nicer gold earrings and I try to take them out as soon as I get home so not to keep them in to long to let my body get to irritated.