Don't sweat if you don't have an outline written. Most of my writing, especially when I'm just starting a book or series, is all done on the fly.
*nod* Outlines are tools for keeping everything in one place and roughly connected, to my mind, not only do they not have to bear much resemblance to the finished product, but for me if they do, it means the book's not got enough life to be surprising me and that's generally a very bad sign.
I'll note, which I haven't for a while, two writers with successful careers of a few decades in genre who occupy extreme positions on outlining which they have talked about in public; Tim Powers outlines his every book down to what happens in each conversation before writing it; Steve Brust makes it up entirely as he goes along, and when he gets stuck, will write about the characters having meals and bitching about being stuck and so on until he gets to the next bit of plot and then cut as apt. He appears to be as in the dark and as fascinated by how his creative process works as any of his readers; if you've read
Cowboy Feng's Space Bar and Grill, the bit with the goat was something he deliberately included as a throwaway early on specifically to see how his subconscious would make it important later in the book..