What Does Cramping During Pregnancy Indicate?

I am 32 and this is my 3rd pregnancy. I am about 6 weeks and have my first doctors appointment next week. However I have been cramping severely for the past 2 weeks. It is worse when I have to urinate or have a bowlmovement. Also I get a lot of lower back pain and abdominal pain on the right side. I ve never experienced this before.