It's possible that you are experiencing post partum infection, which is estimated to occur in 1-8% of all deliveries. Endometritis is the most common source of postpartum infection. Other sources of postpartum infections include :

postsurgical wound infections
perineal cellulitis
mastitis
retained products of conception
urinary tract infections (UTIs)
septic pelvic phlebitis

I'd suggest that you follow up with your OB-GYN and request diagnostics for the abdomen pain.

my guess would be a UTI. I would schedule an appt with your doctor just to make sure. Are you having any other symptoms like burning when you pee?

sometimes UTI's creep up on you and you dont know you have them.

congratulations on you new baby!!!