Lump on leg

[Kevo5684]

So i noticed a lump on my leg it's on the left side of my right leg just under my calf it just showed up. It's firm a little tender to the touch it's a little tender around the lump.
I actually went to my gp and he took an extra that he said looked fine and he also did an ultrasound. The untra sound from what I understand didn't really show a hole lot. He said he didn't see a mass ?! He told me it's just swelling in the soft tissue and to take ibprofen for 5 days and it should slowely go away. But I'm still freaking out
Would a utrasould show if there is a mass or something there I'm scared to death of sarcoma and if I knew for sure there isn't any mass I would be at eease I think
He did say I don't see a mass but he also said ya know there is a chance for other things like lipomas or sarcomas but i wouldn't loose sleep over it
Well I am I'm scared any help would be greatly appreciated