Preeclampsia Questions

Question ladies -- I just came back from the ER for a pinched nerve in my shoulder. While at the ER, my BP was running 155/108ish, which is high for me. It's never been higher than 134/88 during my pregnancy and was running as low as 112/60 during my second trimester. However, i was also stressed and in a lot of pain.

Now I'm back home and just feel like i can't catch my breath. I have had extreme swelling for a lot of my pregnancy and my blood pressure has been perfect so I can't really go off of that. How did you guys know If you had high blood pressure?

I'm 39+2 just FYI.