This pregnancy is so different from the last!

I seem to be quite short of breath, even jsut sitting still, I feel I can't quite get a breath in. No heart racing or faintness, jsut feel puffed doing nothing. Wuga2 is transverse and sitting high, but I am only nearly 22 weeks. What is this going to be like further down the track???? Is it just because he/she is lying that way that this happens or could it be something else?