Officially over a week late

I'm officially over a week late (8 days), have creamy white cm and no sign of a period at all but I got a negative test yesterday and today! Yesterday's test was frer and today was clearblue digital. I'm not stressed, never this late and if I didn't get preg this month I was planning on starting clomid with <a href="">iui</a>. Is it possible I'm pregnant just isn't showing on hpts yet?