AF 4 days late, spotting, and BFP? Help! 😱

AF was due on Tuesday, I have been testing for the last week and getting some very faint lines and some negatives. I tested Tuesday morning and had a very very faint line but barely anything there. I started spotting on Wednesday so I thought AF was about to start, so I didn’t test again. Well it’s now Saturday and have still just been light light pink spotting so I decided to test again. BFP this morning, has this happened to anyone and still carried a healthy pregnancy? Or should I be worried something is wrong? With my first pregnancy I had no bleeding/spotting at all. Thanks in advance! Picture is the test from this morning.