Hi This Is Quite Shocking But My 12 Year Old

Hi this is quite shocking but my 12 year old daughter is 12 day's late for her period she started them on the 29th July another 26th August, 26 September an the next 26 October but nothing November. Shes has a boyfriend and has said intercourse has happened twice. I have done about 6 tests about 4 have had really faint lines and a couple ha've been negative. I have felt her stomach and it is really hard at the bottom. Her complexion has turned a little spotty last couple of days aSewell. what does this sound like?