I had unprotected sex on 8/08 and was suppose to get my period on 8/09. I keep emaculate records of my cycle, even recording it on my calendar. However, I am now 12 days late. Is it really possible that I am pregnant

Of course it is possible, women have their ovuation at different times, some women can even get pregnant on their period.

It may be too early to test at this point, so you will have to wait till next period and see if you miss it, then test.

Also some women just miss a period, for others they can vary of days every now and then