Strange lump in lower abdomen??

Hi, so for quite some time now I have had a weird hardness/lump in my lower abdomen. It's located just above my pubic bone and it feels hard to touch. It's where my uterus etc is, but I'm not pregnant as I've felt it for quite a few months now and all negative tests, also use contraception. It comes and goes, mostly comes, usually along with bloat, and I can still feel it when I'm lying down. Any ideas what this may be? Doesn't cause much discomfort but I had an ultrasound scan and the doctor said it was nothing but it's still bothering me!!

If you still worried about the lump, you can see another doctor and had an ultrasound again. If there's still nothing found, you can be ease and wait for the lump disappears itself. 

  Chole  if  i were you i would get a second opinion it is always better to be safe than sorry

Thank you for replying, I think I will go back to a different doctor, just getting fed up of hearing there's nothing wrong when I can feel that something is!! Thank you

Thank you for replying Caroline! Will be making another appointment for it soon, just don't want to be told it's nothing again!