Car accident with baby in car 😭

Today I was at a stop sign and an old lady hit us, I freaked out because my baby was in the car. She then drove off and left us there and I wanted an ambulance to come to and check out my baby. He cried for a second I think just from the sound but then didn't cry and he appears fine. The ambulance people looked at him and said he is fine they don't think he needs to go to the emergency room but now I'm just so scared that they told me he's fine what if he's not? Should I have took him in. My bumper got messed up and it definitely jolted us, but the paramedic said with his type of car seat he most likely didn't even feel it it just scared him. Now I'm sitting at home worrying that I should have brought him in. He's 5 months. (They did catch the lady and she is now going to jail for fleeing the accident scene.) 
Update: I brought him just because I was too worried & they checked him out and said he's perfectly fine & healthy as can be. So glad now I don't have to worry anymore! Thank god for car seats!Â