Faint lines & AF due tomorrow

Katie

So my AF is due tomorrow the 21st...but ever since yesterday morning I've had a faint second pink line. I took a HPT yesterday morning, last night, and this morning-- all show the same very faint pink line. My question is....will the line get any darker??? Or is that my BFP?

Advise please! I've never had any sort of a second line on a HPT...I fell it should be darker....but maybe it's still early?

***I've used 1 curved FRER & 2 regular FRER

Xoxo