Writing Ideas Drying Up

You know what scares me? That I haven’t had many good story ideas for a long time. By story ideas I mean short story concepts or ideas to put into the novel. I used to have post-it notes surrounding my desk, but that slowed down this summer and eventually stopped. I don’t know why. I don’t know where they come from – they’re flashes of inspiration that either happen spontaneously or from thinking about something else (“hey, that would be good to put into the novel”). They’ve dried up. I don’t know where they came from, so I don’t know how to bring them back.
What’s changed recently – well, had a daughter, and that results in some lost sleep, but since this started in the summer, I can’t firmly pinpoint that at the cause. I’ve had a designated writing time every weekday for forty-five minutes, and whenever else I can. I don’t know. Maybe I haven’t been thinking about the stories lately – that usually prompts ideas. Maybe my focus hasn’t been on my writing. Maybe it’s just a dry spell.