I haven't read every reply, but I want to echo what LizRR said. It depends on what you were doing pre-pregnancy.

My first 2 babies I was not running pre-so I basically just walked and worked (I do have a physically active job). I started running after my 2nd baby. When I got pregnant a with my third I had hyperemesis and I could barely bath let alone walk or run for exercise.

But this time around, though I was still sick, it wasn't nearly as bad as my last. I still wasn't up for running the first trimester, but yesterday I went for a very easy light walk/jog to test the waters and I was surprised at how good I felt. So today I am going out for a run pushing the single jogger while my older 2 are in school. Many women run right up to delivery. Seeing as I am always so sick during the first trimester, I feel like I got cheated out of the time when my belly is still small to run, so I'm hoping to continue running most of my pregnancy. And if not then I have a bike for back up.

With the exception of I believe some abd exercises, almost anything is pregnancy friendly if you have been doing it before. :)