I did something similar about 20 years ago and even now it doesn't take much to tweak my back again. In fact I'm dealing with it right now along with a pulled muscle and/or a pulled or torn ligament in my lower ribs.
It doesn't hurt to call and talk to a doctor. My dad ignored/lived with some back pain that should not have been ignored. He ended up with emergency surgery and then a year later 30 days in traction followed by two more surgeries within a week. He has so much hardware in his back that they had to reinforce his lowest vertebrae with cement. My best friend's mom has had to undergo multiple back surgeries in the last year and is filled with hardware as well.
Be careful not to reinjure it. Be careful with lifting and twisting. Gentle stretching is good. If it hurts, stop. One of the best things for me is to stand with my back to the wall and kind of squat until my back is flat against the wall. Hold it until it becomes uncomfortable.
Start with ice, but after a few days use ice or heat--which ever feels best. Ibuprofen, even if it isn't hurting right then.
Alternate between sitting and standing when possible. I'm a teacher, so I try to sit for no longer than 15-20 minutes and try not to stand for more than 15-20 minutes. When sitting, be sure you have good back support.
Sleep in whatever position is most comfortable. This time being flat on my back with my knees up is most comfotable. Last time it was sleeping on my right side with a body pillow behind me to keep from rolling over. Be careful getting out of bed. Roll to your side, use your top arm to push yourself up, slide your bottom arm up so you are resting on your elbow. Push up to a sitting position. Then swing your legs over the side of the bed. You can probably find a diagram online.
Also be careful getting up from chairs. Use your legs and arms to push yourself up.
Talk to a doctor before seeing a chiropractor or getting massage. Depending on what type of injury you have a chiropractor or massage could aggravate it more. The last time mine acted up I ended up doing physical therapy (stretches to strengthen core muscles, therapeutic massage, and EMS-electrical muscle stimulation). Both that time and this time my doctor told me that the type of injury I had would not have been helped by a chiropractor and in fact the manipulations could aggravate the injury more. If my dad had seen a chiropractor the manipulation may have speeded up what led to his emergency surgery or have caused a stroke.
Good luck! There isn't much that is worse than back pain.