What happened?

This morning, I woke up with my regular aches and pains, heartburn and cramping and then the big urge to pee. I used the restroom and went back to my bedroom to lie back down for a bit, and that's when I noticed the back pain, it was in my upper back. I figured I had slept on it wrong, so I got up and walked around the room trying to stretch out my muscles. When that didn't work, I took Tylenol (the pain was getting more intense). I lied back down to see if that would help, and then this sudden tightness came over my chest and upper back and under my ribs. I couldn't breathe. All I could do was scream. It woke my husband up and he started getting dressed ready to rush to he hospital (he thought it was labor), but I couldn't move. I was in so much pain and could not catch my breath for anything! I stretched out on my bed and rocked back and forth screaming and moaning until I fell asleep (I guess the Tylenol kicked in, it had been about 30 minutes since I woke up), and when I woke up an hour later, the pain had vanished. Now I just have a stiff neck. Has this happened to anyone else?