The first day of my last period was April 30th. My period was due on June 4th, it is now June 12th and no signs of my period. I have never been more than a day or two late for my period. But 8 days is a bit much. I took 3 pregnancy test and they were all negative and I haven't experienced any real pregnancy symptoms except for a little fatigue and breast tenderness. Could I still be pregnant?

So, your not on a 28 day cycle? Starting on the 4th would put you at a 36 day cycle. I would call your doctor.
28 days would have had you start on the 27th of May and you would currently be 16 days late. I would imagine that your hormone level would be high enough for it to show on a HPT - but you never know with those things.
Just call your doctor and have them check it out.
Good Luck.

I agree with NowWhat. I would call your doctor and tell him/her what is going on. Are you young? It is not uncommon, if you are young, to sometimes skip a period.

Yes a 36 day cycle is long, are you sure you have that right? I agree with the others. Get to your doctor and have them do a blood test.