I am so sorry to hear that your son is not feeling well. I hear your concern about giving him Nurofen (ibuprofen) and can absolutely recommend that you do give it to him. over a short period of time it will be no more harmful to his stomach than bring sick has been. in addition, the pain relief may allow him to eat something. if you can get him to take it then I would go ahead. another option is to give medication by suppository. Paracetamol and ibuprofen may each be available as suppository. This is an excellent way to provide pain relief for a child with mouth pain. They are even a bit more effective this way since they are absorbed even better than from the stomach. Luckily, though you could be infected, parents are usually safe from this infection and I suspect it presents little risk to your unborn child. I hope your son feels better soon.