has this happened to anyone else?

Rachel • 🇨🇦 40, TTC#1 for 30mo, 2 miscarriages. 👭🌈
One week ago yesterday I had a blood test to confirm my early pregnancy.. the Friday they asked me for a urine sample... numbers doubling! They asked me to take a home test Monday and Thursday (today - at 4w5d). 
Monday - line was darker than the faint "is it positive???" Line that I got prior to my blood test... 
today; however, the line is faint again! Same test as Monday... same box! (First response)... I've had some spotting yesterday and a bit darker (more red than pink) today... I try not to get myself worried about this sort of thing, but because this is my first and only pregnancy, I'm a tad concerned... anyone else experience a VFL after a confirmed pregnancy?? 
Also, I have an ultrasound booked for the 22nd.