38 weeks and 5 days

I've been having terrible lower back pain... Every time I turn a different way the pain stays there and it just hurts so bad, I've been having cramping in my lower stomach also on top of it I threw up twice and this has been going on for 3 hours... I cannot sleep or get comfortable no way. I'm a first time mom can someone tell me what this may mean ? What's causing it ? Or what I can do to make it better