BFP today!

Samantha • 29. wife. pregnant with baby #2!
So I've felt a little sick that past week and my boobs were a little sore last night. I woke up crazy early today and something made me just grab a test 2 days before AF. It's a digital one and sure enough when I flipped it around, it said the word I've been hoping for! 
A part of me is still a little nervous that it's a false positive or something so I'm trying to get in later today for a blood test. 
Has anyone had any problems with early pregnancy tests? Glow says I'm about 3 and a half weeks along.