Faint positive hpt tests

Im ttc baby #2. I've been through 2 miscarriages. The first was at 12 weeks and last one was at 6 weeks just back in April.

Last night and this morning I got a very faint positive. My period isn't supposed to start until Thursday. The last time I was pregnant the tests were very faint and it ended in a miscarriage.

I guess I'm wondering if because they're so faint, does that it means it's not going to stick?

My doc said to test again tomorrow with fmu and if I get another positive to come in for bloodwork. Then she'll test again Friday to check if my levels are rising.

I also noticed that the control line is thinner on the bottom test but I'm not sure if that matters.

My daughter is 3.5 yrs old and I found out when I was already 5 weeks prego with her. So my ttc experience has been much different. I just want a healthy, full term pregnancy!!!!