Line isn’t changing?

I’ve had 4 miscarriages (3 ttc my first child and 1 ttc second) so I usually don’t need to ask any questions, but this has me puzzled. I tested the day after my period should have started and it was negative. Had a super short period that started the next day (mine are typically 7 days) so I was worried bc my last pregnancy ended with a short period and then my levels continued to rise for several days before finally dropping and having a full period. Out of curiosity I took a test and it was positive. That was last Tuesday and on Wednesday morning I took another test just to check and it was a strong, noticeable line. Now 5 days later my line still looks exactly the same. Not darker but not lighter. Has anyone else had this happen?? Did you end up having a miscarriage? I had bloodwork done on Wednesday and my levels were at 45, but I won’t repeat it for a week so I’m stuck wondering about it every minute of the day.