Keep in mind that when you are on hormonal BC--such as the patch or the Pill--the week you don't take BC and then bleed is NOT a real period. It is "breakthrough bleeding" due to hormone fluctuations. You can't have a period if you don't ovulate, and you don't ovulate on BC.
What will affect when your real period returns is (a) how long you've been on hormonal BC; and (b) how regular your real periods are, when you're not on hormonal BC.
Your body has more to adjust to than you taking off the patch on 7/30. The longer you've been on hormonal BC, the longer your body may take to get back in the swing of things and ovulate, thus producing a period.
When I went off the Pill after 10 years, it took me several months (like 3 or 4) to get a regular period again. I would bleed for 2 weeks straight and then not start another cycle for 50 or 60 days. But that was my experience--some women's cycle snap back within a month or two.
I guess if I were in your shoes, I would use non-hormonal contraception until you can track your cycles, especially ovulation. It might only take a month or two. If you get pregnant very soon, you and the doctor could end up arguing over how far along you are. (This has happened to women I've known.) Also, with absolutely no idea of where you are at in your cycle, how would you know when to take a pregnancy test? What would you gauge as "late"? Just food for thought; take it for what it's worth, and good luck!