Cramping and backache.

Brenda_b
Hi everyone, I'm 25 weeks pregnant and a first time mom. My pregnancy is considered high risk due to my high blood pressure (I had it before I got pregnant) and my age, I'm only 20. I've been having trouble its mainly seems to hit at night but I get really bad cramps, and my back feels like its getting cramps too, but then after about 20 minutes it'll go away. It normaly wakes me up from my sleep, and I normally end up crying because it hurts so bad. I was just wondering if this was normal or what could be causing it. I'm really worried about it, because its happened a few times before, however it went away the first time it happened, and it hasn't really gone away. I'm still cramping (a little) and my back feels like I'm getting crushed.... Any advice?