BBT question

Jackie • TTC #2 with a 5yo Clomid baby
I've been tracking my bbt for the first time this month. What are some things I need to know? I am now 14 dpo and my temp is still above the cover line. How long does it need to stay above to be pregnant? (Obviously I would test as well, I'm just nervous to test because I don't want to be let down!!)