Thank you for your question. It is not common to have noticeable "bumps" with a yeast infection so the possible missed diagnosis on your prior visit could have been wrong. Yeast infections are usually just sore, itchy and cause discomfort. Bumps are generally associated with herpes.
There are instances that you can come in contact with someone who has herpes and not contract the STD however, in most cases if that infected person has a breakout, then this is the main way that herpes is passed on to the next person. This may be why the others involved are not coming up positive or in reality, they could be lying too.
If you have concerns about a possible misdiagnosis, you will have to wait for another breakout and go back to your doctor or get a second opinion. We cannot diagnose you on here as with herpes, you must have visual inspection and tests ran on the bumps in order to fully understand the diagnosis.
I hope this helps.