Feeling unsure..

I really don't know what to think, I hope someone can tell me what they'd recommend... we had sex mon sept. 28th and wed sept. 30th. Last tuesday 10/6, I started spotting- this was 5 days before my expected period. I spotted for 2 days. Does this sound like implantation bleeding? My period was due yesterday, and I still haven't gotten it. Every test I have taken has been negative, including one I took today. Could I still be pregnant but maybe need to wait a few more days to test again? I just feel so confident things are going the way the should except the positive test....not sure what to do =/