Hi, Thanks for writing in to us. As you are on warfarin treatment for post partum pulmonary embolism, your blood is thinner than normal. During CT scan there might have been local pooling of blood beneath the skin surface.As you have written in, there is swelling and inflammation at the injection site. You have developed a superficial phlebitis (inflammation of superficial veins). This is an uncomfortable situation bit not a serious one. Symptoms depend on the location of the inflammation. Superficial phlebitis can cause symptoms such as: •Redness along the path of the vein •Warmth, tenderness, or swelling in affected area •Itching or burning in affected area •Low-grade fever. Self care measures can help relieve symptoms. Conventional treatment usually involves elevating the affected limb and applying warm compresses to ease discomfort. Compression stockings may also help alleviate pain. This is a self limiting condition. If there is increase and severe discomfort, please consult your doctor regarding warfarin intake. Hope this helps.