3rd pregnancy and I feel a little off..

K
I'm 6 weeks today. I just have an off feeling this time. With my first 2 pregnancies, my symptoms weren't as noticeable I guess. This time every ache and cramp is making me nervous, and I think the worst is going to happen. I've had very light cramps and dull pressure in my lower abdomen since 4 weeks, before I even took my test. It almost felt like my period was about to start any second. They finally started to subside a couple days ago, thankfully. Everywhere I've read said that these cramps are normal. I don't remember having cramps as a symptom with my first 2 though. Im also getting a light pain in my lower back, it just comes and goes randomly. I don't know why I'm so freaked out this time. Literally everytime I use the bathroom I check for spotting. I've been trying to take it easy, and just relax, but my anxiety is getting the best of me. My first appointment is this coming Tuesday, I just hope it goes well and everything is okay.