Sign of miscarriage or normal?

I’m posting this just because I am worried. I am soon to be 8 weeks pregnant and this is my second pregnancy. With my first pregnancy I had no symptoms at all but before I found out that I am pregnant now I threw up for a week straight. Well I been having light cramping. Yesterday I had workout because I workout all the time and didn’t think it would be wrong too and later on in the day and today when I stand up I had extreme intense back pain to the point I had to lay down and couldn’t move. I have an obgyn appointment on the 13th and figured I’ll wait until I go there to express my concerns. I just want to know has anyone ever experienced this and should I go to the ER instead of waiting? Could this be a sign that there is something wrong with my pregnancy?

Also I did not workout today it was just yesterday but even today I got the same exact back pain and light cramping.