How Should A Leg Lump With Twitching, Spasms And Puffiness Be Treated?

hello I have a lump in the middle of my lower right leg on the inner side of my muscle. This all started a few weeks ago with twiching in that area that was off and on but seemed to happen more at night. Its like a little area of my muscle was having spasms on and off and sometimes they would last a pretty long time, like pulsating or mini spasms. Now my leg is kinda puffy in that area and i can feel a lump in there like on my muscle. I went to the ER and they checked for a clot and said they didnt find any but it just keeps doing this and im starting to think they may have been wrong or something. Sometimes it hurts but that rare its just always twitching and nothing i do helps it so if anyone has any clue to what this may be please let me know thank you so much