5 weeks. Back pain and fainting

I am in the middle of switching doctors, and I can’t decide if I should go to the ER or not. I am only 5 weeks pregnant (but miscarried 2 months ago around 6 weeks.) Just like last time I have had pretty steady cramps in my lower abdomen and back, I was told this is normal from all the changes happening. But today while I was at the gym I had to quit my workout and leave because my back pain had become so severe. When i left I went to go grab lunch, and while in line I had to leave and go sit down because the room starting spinning and became very blurry followed by cold sweats. I’m curious if this is normal back pain due to changes going on or if I should go to the ER and make sure something is not wrong that needs medical attention.