My feet have been swollen

for over a week now! They are killing me! I went to the doc and he did an ultrasound on my foot and an xray and he said those looked fine. Then when I went back in to him I told him maybe it's Nephrosis...a kidney issue. I had all the symptoms and so he tested me for that and said it wasn't my kidneys. So today the dr's office called and said that I had an appt at 3 at the hospital for an Echo Cardiogram. I was like...well I have to work, but ok I guess it's important! So I went and they did an ultrasound of every angle of my heart and I asked the lady how long it would take for the results and she said 24 hours, but because of the weekend it could be longer...and I said well what if it's bad will they call me in? She said she wouldn't let me go home if she saw something serious and she was letting me go home. WHY ARE MY FEET SWOLLEN???? My sister thinks it's diabetes...I PRAY it isn't!! I wore support hose today (THANK YOU SHANNON!) I was able to walk and my feet didn't hurt AS bad, but it is still painful. I haven't looked at my feet tonight...will when I go to bed.