They can be. Here are some personal experiences:
Sure!
Yes, as well as a sign that your period is coming soon but yes, it is a sign of pregnancy.
Yes
Sore nipples can be a sign of pregnancy, or if you're due for a period, your nipples with get sore about a week before your period, if you miss your period, take a pregnancy test.
Yes, Sor nipples are a sign of pregnancy also if you have missed you period
soreitchynipples.com
Yes
Yes and also a sign of pregnancy. PMS symptoms can mimic pregnancy symptoms.
Some women are more prone to yeast infections during pregnancy, and sore breasts and/or nipples is a sign of pregnancy. The sore throat could be related to the thrush (yeast) - but is not a sign of pregnancy. If you are questioning a possible pregnancy you should take a test and remove all doubt.
Nausea and sore nipples, most certainly. Car sickness, not so much.
Not always no. It can be a sign of nipple irritation or infection.
That can be sign of pregnancy or PMS. All women are different.