I'm sure this would affect my rankings but I'm not sure how badly... I have a blog with about 2-3 months of posts (75 total) and I'm about to move that blog to a domain... So should I do this? Is it worth the loss in indexing? I'm hoping that at a domain, I have better control and my rankings over time will improve further than they would at blogger.com... Has anyone done this?
If you're doing it through Blogger Custom Domain, You'll get an HTTP redirect from the old URL, so the search engines should understand you've moved. At least Google will index your site quite soon. If you're going to do it, do it sooner rather than later.