It's not your womb. You may have strained a muscle, which can be very painful from lifting improperly. Next time use your legs to lift heavy objects, not lifting from bending over using your back. You'll have horrible back problems if you continue this way. Just relax and take pain medication if need be. Good luck
http://m.youtube.com/index?desktop_uri=%2F&gl=US#/watch?xl=xl_blazer&v=6Y-LXX13iN8
As to stop the pain take a ibuprofen of tylonal. Somthing of that sort. If the pain is still there for more than 12 hours or intensifys go straight to a doctor. Unless by than you can tell it's just soar muscles then no need to rush to the doctor. Also if you do devloup a bruisse in that area you may have internal damage and you should be taken to the er right then and there. Hope I'm not scarrying you. I'm sure it's nothing more than a torn muscle. Those can extremely hurt.
~libby