Scared to miscarriage

So I’m 5 weeks pregnant tomorrow and I’ve had my pregnancy confirmed by doctor my first ultrasound is feb 13th. Well I’m a poas addict. And I like to watch line progression but this time it’s like the lines are getting lighter and not darker. Should I be worried I had a miscarriage 6 years ago at 7 weeks pregnant and I’m scared I’m gonna miscarry again. Any hope or peace of heart for me. I’m freaking out.