Hello, I would be happy to help you with your question.
Here are the issues:
1. Concerns regarding a bladder infection - you need a urine culture
2. Concerns regarding a rubella
infection - the IGG
positive suggests that the baby is protected
You need to schedule a visit to check the urine and discuss repeating the rubella titers in 6 weeks. Also ask about a targeted scan at 20 weeks to fully assess the baby. I do not think there is significant reason to be concerned, and sometimes the labs related things like rubella can be confusing. You need to address these concerns with your doctor and see if they think the above plan would be reasonable.
I hope that this helps and good luck!