I Fell Two Weeks Ago And Hit My Shin Pretty

I fell two weeks ago and hit my shin pretty hard. I have lots of swelling - went to ER they did an x ray and. I broken bones but they were concerned with possible blood clot - they weren't able to do an ultra sound that late and sent me to a nearby hospital for an ultrasound - whew - no clot, however, I am still have serious swelling. And the knot is huge on my shin. I called the ER they said follow up with my dr. I've called and left a message - no answer yet. Just tried again and busy
If this just takes a while to heal that is fine but it still hurts quite a bit and the swelling is a concern as I don't want to ignore if it could e something more serious. My sister says I should insist on a ct or MRI as some clots do. It show up on an ultrasound???