I am allergic to yellow gold (so was my grandma). It will almost blister me, and also cracks around bubbles. I found this out with my first wedding band. It was thick band and had birds and flowers inscribed around outside -so pretty. Right beneath it occcured the rash. I was not pregnant either. Then my mom told me about my grandma. I also have nickel allergies, by this I mean sometimes the rivets in jeans will cause a (small, not the crackly blisters) skin reaction. THAT SAID, I can wear white gold, platinum, and good sterling. I cannot wear necklaces AT ALL (they stain my neck in the collarbone hollows!). I have to be careful with earrings too - do not sleep in them, only GOOD gold/metals and even then I sometimes will get weird breakout below. (Earrings are my weakness though, since I cant wear necklaces of metal)
Nickel is often used in jewelry; gold or sterling alone is soft, other metals are used to strengthen.Sometimes nickle does NOT bother me which leads me to believe what I put in my mouth can affect it, but don;t know what. But pregnancy does do weird things, maybe yours will pass. I had to change perfumes every time I was pregnant! I am surprised the jeweler did not mention gold allergy! IF the ring didnot bother you this way for a long time before, I would assume it will/may change when yr body is all back to not preggers stage. But remember - just because you were never allergic to something before does not insure future protection. This applies to everything! Pollen, medicine etc. I was not allergic to penicillian until I was 35, but man I AM NOW! I know you hate NOT to wear it, but I suggest going ring free til finger is normal and try again. If still isssues, consider another type of gold? OH! and if i wear FILAGREED yellow gold, it will not blister me, but it can breathe see? And filagree is weak, not at all suitable for a wedding ring. I just avoid yellow gold and low carat gold, sounds snooty but Iam so not ! (: Good luck!