I had a mc nearly 7 weeks ago now and ive been getting random pregnancy tests.

After 3 weeks I finished bleeding and went back to completely bfn tests. I’ve tested everyday since and over the past few days I’ve noticed that I get vvvvfl at random times. This morning I had a bfn, no faint, nothing. The bottom two pictures are from this afternoon where to the eye the line was very visible. The top two and this evening- which is a bfn! I’ve had this now for nearly 5 days. Sometimes the line is darker or sometimes a whole day will be zero faint lines. Just realised confused. HCG is back to zero btw.

Any ideas? Anyone else been through something similar?