Is this normal?

Ok so on 8dpo and 9dpo I got very faint lines on frer tests. I don't have any of those type left (and haven't had a chance to go buy more), so I decided to wait a couple days and test with my Clear Blue digital at 11dpo..which was negative. Is it normal for it not to show up on a digital for a few days after receiving a positive on a first response?