Faint lines after miscarriage in july

Winter

So we lost a pregnancy at almost 12 weeks in july (babies didnt develop past 8 weeks tho). I was devastated and because I have gone through other losses I knew that my body was capable of miscarrying on its own so it did not go back to my follow up visit and I have not taken any pregnancy test since but I have had what I believe to be 2 cycles and spotting ever since until about 3 days ago the spotting stopped. for whatever reason I decided to take a pregnancy test yesterday morning and it instantly came up with a super faint line. I used another test with the same urine sample just to make sure that I wasn't imagining it I guess. And then I took another last night and this morning. I know it has not been much time since I took the 1st one but I still feel like there has been line progression. My levels were upwards of 78k when my hcg was last taken in july but by now that should have gone to normal unless I didnt completely miscarry right!? So should I take this as a new pregnancy?? I actually have an appointment already set for Monday with an ultrasound because I was somewhat concerned with the continued spotting but should I call to tell them or just see what happens? I'm so confused and trying to not get my Hope's up too much!

Just wanted to add I have Uterine didelphys too so it is normal for me after giving birth for my cycles to take time to synchronize too so spotting could be from that also.

Picture from left to right is newest to oldest (couldn't get it to turn)