If your boss can't approve you to WFH is HR able to help? I would have thought that any staff who can work from home should be permitted to. Regardless of the pandemic, when you are so close to popping it's reason enough to have you stay home in case your water breaks in office...
If bopian have to go back, don't over worry too! You're vaccinated and so are your colleagues, ventilation has been revamped too. You can also take extra precautions eg sanitize work station regularly, don't mingle maskless, double mask (cloth over disposable) while commuting, and dapao to eat in an empty room to avoid the crowds. Jiayou!
Huiling Yeo