I'm kind of having a similar problem. I'm a senior and I didn't get in for C/O 2018, so I am re-applying for C/O 2019. I used my junior year English and math teacher, and I at least know that my English teacher's rec was good. I didn't get their recs until the beginning of senior year, since I started the application late.
Now, however, I'm in a tough situation. My math teacher got switched mid-year to teaching a different class (because one of the teachers retired) and I've only had my new, current math teacher for close to a semester. He's young and I don't know how good he is at writing recommendation letters, especially since he hasn't known me that long.
My English teacher is very liberal and sees the military as a killing machine and political pawn. He was in the Army, so I don't know why/where his accusations come from. Whatever.
I would consider myself a good student and I have had a few respectful discussions about the military with him throughout the school year. He is very good with words and I feel like he could write an awesome letter of recommendation, but the thing is, it would be for something that he doesn't support, so I don't think it would be good to ask him.
My question is: Should I wait until I know my math and English professors at my college this Fall? I know college kids sort of have to anyway wait because their transcripts can't be sent until after the first semester. I know USNA takes college recommendation letters, but is it bad to wait that long for them? I would have everything else completed on the application by then.
Sorry for the long post, I just am not sure of how to handle this "unique" situation.