I am the lady that Kate mentioned in the post above and speaking from experience, I don't want to panic you, but I would definately NOT wait a week and a half to see your doctor.
I get sciatica all the time so I didn't worry about any leg pain etc that I got. I too am carrying low.
I starting getting very breathless too, something as simple as getting up to go the toilet was a task in itself. I would get very breathless and could feel my heart rate was up. I put it all down to pregnancy until I was in the shop one day having a breathlessness episode. I went to the chemist, they took my blood pressure etc. Blood pressure was low, but pulse rate was high, I also had mild chest pain (which I had put down to asthma being an asthmatic) anyway to cut a long story short, sent me to a medical centre who sent me to the hospital.
Days later after my heart was checked out and given the all clear, I am being treated for a blood clot in the lung. I sometimes wonder whether I might have put the pain in my leg down to being sciatica when really it may have been a blood clot. As I said, I don't want to panic you and this is my experience, however I do believe it is worth you getting it checked out sooner rather than later. I was not getting mine checked out as I had put the pain, etc down to pregnancy, but really glad I did and have now been symptom free for one week and been able to breath again.
Sorry about the long post, feel free to PM me if you wish and please get it checked up on.