It's caused by increased blood flow and it's completely normal. It's also referred to as Chadwick's sign I believe.
Yup!
No, that wouldn't normally happen.
Doucheing while pregnant is a very bad idea. This can cause serious infection to the vaginal area, including the cervix, which can inturn, be harmful to you're unborn baby.
It's in the same place as before you got pregnant
They say it's "butter soft" when you are pregnant...
No. Sex during pregnancy is fine right up until the last few weeks.
It is softening of the cervix when omeone is pregnant
Take the tip of your finger and press the tip of your nose. This is how a non-pregnant cervix generally feels. Now take the tip of your finger and press the fullest point of your bottom lip. A pregnant cervix generally feels "soft and mushy." You cannot feel it from the outside.
If you are not pregnant, and not on your period, then it probably means you are ovulating. The cervix opens up when you are ovulating, and it becomes 'slimier' to help aid the travel of the sperm. If you are pregnant, then it just means your are pregnant. If you are not pregnant, and not ovulating, then it means you are about to have your period.
If you are pregnant your cervix will swell and get firmer to the touch. This is due to the entrance being sealed so it now starts collecting fluids inside.
3-4cm
Well I'm 5 weeks pregnant and my cervix is extremely high, medium hard, and closed completely. I hope this helped you a little!