Terrible cramps & diarrhea…?

I’m currently 4.5 weeks. Last night I woke up during the night with such intense pain and cramping that I immediately thought the worst - it was the worst cramping/pressure I’ve ever felt. I got up and sat on the toilet, broke into a cold sweat, and wasn’t sure if I was going to vomit or faint or what. I eventually started to pass some gas, which did relieve some of the pressure. After about 5 minutes of wondering if I’d pass out and fall off the toilet, I had diarrhea (no bleeding). I actually felt almost completely normal after that, other than being shaky. The cramps are gone and I slept through the rest of the night. Should I be worried about this? Any ideas or advice?