I agree with MrsD. You really need to have the cause evaluated. There are several clotting factors (labs) that should be checked as well as some autoimmune testing. You should see a hematologist for starters.
MGUS, diabetes, BC pills, and APS (antiphospholipid syndrome) are the first that come to mind. I have MGUS, APS, and pre-diabetes, so I'm on lifelong anticoagulation.
As for the pain, clots take a while (months--all depending on size) to go away. It may be uncomfortable for a while. However, once it starts to decrease in size, you should notice some relief.
If you experience any shortness of breath, get to the ER without delay.