L.W.
Pat,
Please call your OBGYN and tell him/her what happened.
If it bothers you, you should really consult with your doctor a.s.a.p!
I've had two c-sections and the scar can become tender at times (even many years later) but this is something a doctor should really determine. Just a phone call to start... it doesn't mean you'll end up in the hospital.
Best of luck and congrats on your new addition!