Yes without seeing you it's very hard to tell exactly where your talking about.
A physical assessment would be helpful, and an Ultrasound to be sure if there is still confusion following that.
for some fun you could also go to an anatomy website and have a look around in that area and see if you can identify the structure you think may be involved.
if it's been 4 months and it isn't going away - then it's unlikely to go away without some form of intervention so you have to weigh up how much it truely bothers you... and seek help as you see fit