What Causes Severe Pain In Wrist And Shoulder Post A Blood Test?

I had blood drawn for lab work 4 days ago. She collapsed the vein to my left arm. There s very little bruising and very minimal swelling. It s been quite tender but nothing terrible until last night it became very painful radiating down to my wrist and up to my shoulder. The pain will wax and wane - not necessarily with movement but slightly more when I flex the muscles - and is so painful, it will stop me my in tracks. I m a 42 year old very healthy woman with no significant medical history. 5 6 130 lbs. with a high tolerance for pain. Any concern that a clot developed? And, if it s nothing, what can I do to alleviate the symptoms and how long would you expect this to continue?