Welcome to the Forum and thanks for your questions. I'll be glad to comment
Bubbles in the urine are normal for many people. There can be associated with dehydration which causes the urine to be a bit more concentrated than normal, interaction of chemicals in the urine with things already in the toilet or toilet water, and are sometimes unexplained. There is no published association or bubbles in the urine with HIV or any other STI.
Your tests are conclusive. Persons with negative tests any time more than 6 weeks following an exposure remain negative. There are no instances in which persons with negative tests more than 6 weeks following an exposure then go on to develop positive tests. You are in the clear and do not need further testing.
Given your negative tests, nothing about your exposure over a year ago puts you or your wife at risk for problems with your plans to have a baby. Put your encounter a year ago behind you and move forward without concern. EWH
@ Norvec
