What Causes Congestion In Ear?

When I talk my voice sounds congested in my right ear but my hearing is perfectly normal. I can also breathe fine through that side of my nose. I have a permanant hole in that ear drum so I know there is no fluid in there or it would be draining out. No ringing, pain etc. It seems to come and go throughout the day. Sometimes it won't happen at all and sometimes it lasts for several hours. I'm 14 weeks pregnant. Is this just normal excess mucus that some women get when thery're expecting? It's making me a little crazy.