Every pregnancy is different. Every woman will experience pregnancy symptoms differently. If you are a first time mom, I highly reccommend purchasing or borrowing an up-to-date copy of What To Expect When You're Expecting. I am a mother of four children myself, and when I was pregnant with my first child, who is now ten years old, that book was a godsend for me.
It could be. My symptoms subsided at different times I'm not sure exactly when but the extreme breast tenderness that I felt at the beginning of my pregnancies didn't last. Symptoms like that can always come and go or change, but if you experience any bleeding or are worried you should contact your doctor.