It's possible, but I wouldn't trust the digitals. It sounds like you may have gotten a bad box of tests. To be sure, grab a box of regular pregnancy tests. I always suggest First Response Early Response simply because they're easy to read and the pink dye is a lot easier to interpret than blue dye tests. Test with these and trust that result. Remember, digital tests need a lot more HCG to turn up positive than regular pregnancy tests do so it could just be that you're not far enough along from a digital test to pick up the pregnancy yet.