This is something I know a lot about. I have had two DVT's, one in 2003, and one about 16 weeks post partum (which I am still on warfarin for).
Have you had any diagnostic testing? Is it actually a DVT or a superficial clot? Superficial clots often re-occur in the same spot, so sometimes collapsing the vein helps (similar to how they treat varicose veins).
However, if they are DVT's, I would suggest getting some diagnostic blood tests. I am being treated now (and while I was pregnant) as though I have APS syndrome (Antiphospholipid Antibody). My blood work was inconclusive, but apparently with some of the tests the serum can be disturbed which leads to inaccurate results. I am actually going to be tested again when I am off the warfarin. I was on heparin for my entire pregnancy and for 6 weeks PP. I didn't take long for another clot to pop up when I went off the heparin, which is troublesome.
Here is a good link that explains some of the diagnostic blood work that you can have done. I would ask your doctor about it. Blood clots are not something you want to mess around with.
I think the previous poster had some good idea's. I had superficial clots for awhile after delivery but I wasn't worried since they were only superficial. I got one while still in the hospital but did not tell my nurse (bad, I know, but I didn't want to stay longer) If you suspect they are DVT's you can have some pretty bad complicationsif they break loose so you may want to get them checked out.