Strange pregnancy symptom?

Hey!
​Since I was around 9 wks (I am now 22 wks) I have been experiencing a loud thudding noise in my right ear! Does anyone else have experience of this?
​At first it only happened when I lay down in bed at night but as the weeks have progressed it's slowly got worse and I can now here it throughout the day.... It's like I can hear a heartbeat really loud, not painful just SOOO annoying!! Am I alone lol?