5 weeks with intermittent cramping

I found out I was pregnant 6 days before my missed period. The reason I tested was cause I’ve been having cramps. This is my first pregnancy so it just concerns me. The cramping comes and goes and not to intense. I’m also experiencing sciatic nerve pain which I’ve experienced before but from what I’ve read its to early for the pregnancy to be causing that. I don’t really know how “normal” cramping is and what to really look out for with ectopic pregnancies. Any advice?