caveat to Pima's caveat. Some small (population) states like mine; have 2 senators and 1 representative. We haven't had 30 nominees (applicants) for 10 each as long as I can ever remember. In the average cycle, we will have about 20-25 eligible/qualified candidates who can receive nominations. Usually, around 7 will withdraw. So usually around 15-16 actually are receiving nominations. Most candidates will receive 2 nominations. Some get all 3.
Basically; if you qualify, you'll get a nomination. As such, some have received a nomination earlier than the deadline for submitting the application for a nomination. Especially if a candidate receives an LOA, it's not uncommon for one of the MOC's to give one of their 10 nominations to them early.
Mind you, we're talking about a place where there aren't a lot of people. We don't have a 100 applicants for 1 representative or 200 for an entire state. We have 3 moc's; usually around 15-16 getting nominations. So giving some early (For a reason) isn't a problem. That's why I say to check with your MOC. Each one is different. If your MOC is in a district that rarely ever gets an applicant (There are some like that), they will give a nomination early on to entice you to take it. Especially if you don't have much competition and you're almost guaranteed an appointment.