About the lump in my neck.?

i have add a lump in my neck for months now. i got smaller and then it got bigger again. i've been too four different doctors and they all said it was just a swollen lymph node and nothing to worry about. i dont get why i would have it this long though? i had a sinus infection but that was way back in february. i always got a lump on the bottom, back right side of my head. got that about 3 months ago. i went to the doctor about that and he said it was a fatty tissue. it hasnt gotten bigger since. about two months ago i went for blood work to make sure nothing was wrong. its been two months and they still never called back. doest that usaully mean everythings fine? i just dont get what the lumps are? im scared i have cancer of the lymph nodes are something =\