2 wks late but tests say negative!!

So I take proestrogne, it's 10 days on a pill and then you start your period. BUT it can, and have twice, take up to two weeks after the last pill to start your period. Yesterday was day 14, and still no period. I don't feel like I'm going to start. I have taking two test both said no. IF I was pregnant, I'd be around 4 weeks. So that would show up as postive right??? Both tests were the digital tests too. But I don't know if that would make a difference.