Popping your dates into tools on Countdown to Pregnancy, your usual fertile period would have been July 22nd to July 27th.
Obviously, nothing is usual. Your lp can vary within 1-2 days. It's not likely, but it happens. Lp is luteal phase or the time from when you ovulate to when you get your period. Happened to me two cycles ago where my lp went from 12 to 14 days just for one cycle.
You also could have ovulated later for a variety of reasons (as your body gears up to O, if you get very sick or injured or stress then your body might change it's mind about Oing at the time). Personally, I find that only a great physical stress around O time can derail the ovulation process.
I will not say that getting pregnant late in your cycle doesn't happen. My second pregnancy I only DTD at CD 27, the day before my expected period. I wound up pregnant because I had a gigantic cyst on my ovary that I was ovulating from that month, and it delayed my ovulation by two weeks. Hence a baby with my one night stand who I assured I would not get pregnant because who gets pregnant on CD 27?
In any case, if you did ovulate late then it would be too early to test. The earliest post DTD that I tested positive was 8 days. American Pregnancy suggests waiting 19 days post sex for an accurate result (that's the longest it should theoretically take to test positive).
So my advice is that if you think you may have conceived from August 5th, wait until about August .... 19th to be safe and test if af doesn't show by then. FXed all works out how you want and sorry for the long and probably not very helpful post lol
