Buzzy, I think that you do seem to have a low cervix and when you go to Dr ask him to refer you to a gynaecologist, they specialise in this and will be able to check it out and tell you what is what. I did googe it and it could be a prolapsed uterus, but I think your case is not that serious 
Here is a link of a description http://www.mydr.com.au/womens-health/prolapsed-uterus