Hey, I'm in the same situation as you are, and I have talked to my premed advisor allll about it, and I trust her very much. So, yes, you need to submit your AMCAS now, just indicate that you are taking the August MCAT. I have contacted a few schools that I really like and asked them what disadvantage I was at, and they said none, other than getting interviewed later. I think the schools with rolling admissions are the ones that are risky, but if you are a strong applicant, you should be fine. I mean think about it, if a school were to admit all the people they could, then their dream applicant came along with an August score and they had to turn him/her away because they are full, they would be pretty stupid. Just get your AMCAS in and if they send you secondaries send those in as quickly as possible too. You may be wondering if you should apply to your dream schools and risk embarassing yourself with a low MCAT score or wasting money, but I say go for it. You should have an idea what kind of score a student like yourself will get on the MCAT. Also, if you've taken any practice exams yet or have studied, you can kind of tell where you stand as well. Hope this helps. Good luck to you, and me!