4 weeks and cramping

Why doesn’t anyone talk about the awful cramps at 4 weeks? I mean they aren’t constant but I get a really big heavy pain that’s intense, lasts a few seconds and then I just get light cramps and stretching sensations. I have an appointment on the 24th, and I can’t stop worrying that something is wrong. I have hypothyroid disease so that makes me even more concerned. I just need some reassurance, hopefully everything is fine and I’m just being a normal worried first time mom.