Lower back pain

For the past month (or more) I have had really bad lower back pain. I had it once before during the ight and went to my docto the next morning to get checked for kidney infectiona dn it turned out I was pregnant. Not sure if they were related or if it was jsut dumb luck since we were TTC at the time.
I know I'm not pregnant this time so I'm really wondering what it could be. I take cranberry pills everyday, take my b/c every morning along with a one a day vitamin. I take them all together every morning.
Everytime I think it's better or gone it comes back : ( I have an appointment Tuesday since I finally remembered to call during office hours but I thought I'd ask around if anyone else had anything like this?
I don't have any other symptoms other than occasionally I get realy super nauseous in the evenings. A few nights ago I was so sick I tried everything in the house to keep from throwing up. Once I was finally able to fall asleep for a little bit it helped. I've also been getting headaches regularly. They have just started letting up the last couple days.
I think I'm just broken : (