How soon after a missed period can I take a home pregnancy test for an accurate result?

Up to 2 weeks. It generally takes several days for your urinary levels of HCG to get elevated enough to be detected, but it can take as much as 2 wks. Over-the-counter tests aren't always as sensitive as tests at your doctor's office, but even those usually take at least a few days after you're late to turn positive. Recheck a week or two later if you're late for your period & suspect you might be pregnant.