help plz ladies lump!

hi ladies  im  ineed of sum advise,  my period was due 2 days ago and still no sign of af yet, im not gonna test till thursday or friday jst incase af  does come late. but  i have  noticed the pst  few day  a lump  jst under my pubic bone, it doesnt hurt or nething  i was jst wondering if anyone knows what this could be or mean!! iv looked it  up  and it says  it could b the top  of  ur uterus, but  wouldnt that be to  ealry?   as i dont even know if im pregnant yet and if i am im  guessing i would nly be like 3-4 wks gone. any advise would b grat thanks. :)