I think back pain is normal cos our uterus is expanding. But swelling i tot it occur at later stage of pregnancy that I am not too sure.. i am 20 weeks and my back aches like hell for 1-2 days during the 19-20weeks.. every other week, I will get aches for 1-2 days then I feel ok again..
Back pain is normal but not supposed to be excruciating. Ask your doctor, you might get referral to go to a rehab doctor. But swelling on feet may be due to water retention. Avoid salty food. I am on my 23rd week now and no swelling at all.