I have missed my period, am I pregnant?

[randyowens]

My boyfriend and I had sex on June 8th. We did not use a condom for about 30 seconds and then finally put one on. My period usually starts around th 22nd or 23rd and I did start bleeding on 23rd but I am wondering if this is implantation bleeding or if it is my normal period. Skip ahead to July 22nd and my period has not started. I  am now a week late. I have taken 3 hpts and all have been negative (took one 2 days late and took 2 tests 7 days late). Could I still be pregnant or are the hpts correct? Shouldnt there be enough hcg in my body by now to give a positive result?