I Am A 38 Yr Old Who Gave Birth 3

I am a 38 yr old who gave birth 3 months ago. I swelled in my legs and feet the last 2 months or so of my pregnancy but swelled even worse after giving birth. With the swelling there is pain n my foot and ankle, sometimes that shoots up into my shin. The pain comes and goes but my ankle and foot remain tender to the touch. My OBGYN said at my 5 week check up that the swelling was no longer due to pre or post natal symptoms and referred my to my family DR. who referred me to the ER with my history of blood clots. At age 26 I had a blood clot that started in my calf and went into my lung. The Er Dr. did a sonogram on my legs and did not find any signs of blood clots. Also did not find any abnormalities in my urine. I was told to follow up with family Dr. if swelling did not go down on its own. It did start to go down and my left leg is now back to normal. However, the right ankle and foot remain swollen and go up and down day to day. I have a relatively healthy diet and do not take in a lot of sodium and am not taking any medications other than prenatal vitamins as I am breastfeeding. I was on Lovenox injections through my pregnancy and for 5 weeks afterwards. What could be causing the swelling in one leg if not a bloot clot? Please help I have been swollen long enough!!