It's not that big of a deal, but you may need to request an extension if you run out of eligible credits. Usually it's a song and dance, you fill out a form, you go to a dozen offices and collect signatures and you get it granted. But I don't know all the details and what those financial aid officers at doing behind the scenes, but the worst thats going to happen is you'll just have o pay for a few credits out of pocket. I'm pretty sure you're still eligible for loans even if you are over your limit.
Another concern would be to ensure you get at least passing grades otherwise you cold end up on financial aid probation. So if you're getting aid, make sure to commit yourself.