Cramping at 4 weeks

I'm around 4 weeks pregnant with my rainbow baby and having period like cramping. No bleeding but not quite as much CM as I had a week ago. I've been a serial tester and the lines keep coming back darker and darker, here's pics of my most recent tests. I'm paranoid as I had a twin miscarriage at 14 weeks in December and don't want to go through another loss. I shared this in another group too already but am just trying to know if I should be worried or not. I do have an appointment tomorrow but with my last pregnancy I expressed concerns of something being wrong and no one took my seriously until it was too late