I'm 32 weeks pregnant my left arm keeps falling asleep like I deel it very weak. Is this normal?

Have it checked. This weakness does not sound right. There are many body changes accurring in pregnancy. This may include swelling, nerve pinching and others. Your doctor should check this arm weakness as it could point to something more serious.
No. While electrolyte changes could cause muscle cramping, it's not typical to have local weakness. Go to an emergency department. It's unusual, but possible, to have a stroke.