Hi I've Been Having Bad Stabbing Headaches, Feeling Light Headed

Hi I've been having bad stabbing headaches, feeling light headed and sudden pains in my wrist and legs, I'm 24 weeks pregnant so don't know if that could be anything to do with, I've been to doctors 5 times in the last 6 weeks and the have looked in the back of my eyes to check for a brain tumour and said everything it fine there. I'm just getting really scared now to the point where I can't sleep or stop thinking I'm going to die