I have a very small lump on the back of my neck, pretty central just very slightly to the right hand side, also right below my hairline. I first noticed this back in January when it felt a little tender to touch and I had been rundown. I noticed it again end of March but I had a rather large spot on my back at the time, close to the lump so thought it must be linked to that. I've recently noticed it again and just feel a little tired and run down. I'm not sure if the lump has come and gone or always remained there and hasn't been until these points that I've realised it's still there. I haven't really tracked it thoroughly since January as I've put it down to certain things causing it to be there. 
It's very small, not rock hard but not really soft either. It doesn't hurt either, I'm not even sure what made me realise it was there this time around. It seems very positional though, as in when I face forward I can barely feel it but when I tilt my head forwards it's a little more prominent. It doesn't seem to move around loads but I'm unsure because of where it is which is close to where my neck meets my spine, that's why it doesn't move as easily, although it does seem to move with the skin when I push it in different directions. 
I have no other symptoms or things going on either.
I just wondered if anyone had had anything similar and found out what it was? I'm awaiting a GP appointment to get it checked over for peace of mind but have health anxiety since I've had my daughter and every little thing makes me think of something sinister!