I have a sore on the roof of my mouth and my head hurts on that side as well as my throat a little. whats up?

It started as a bump on the roof of my mouth yesterday, about the size of a stretched out dime. it didnt hurt. But today its kinda opened and is painfull and my throat is sore on that side and i have a headache on that side only... is this connected to a sinus problem or whats going on? Im also 35 weeks prego so could that have something to do with this???