My Husband Had Triple Bypass Surgery On His Heart, Just

my husband had triple bypass surgery on his heart, just went to rehab today and its been 8 weeks his chest kept hurting when he would do any thing over 2 mins. the nurse said everything was fine but he needs to see his heart doctor befor he can come back because of his chest pains what can be causeing the chest pains it only hurts when he walks for a short time .