It is ok on my son if he comes jogging with me? He's 4?

I have just decided to start jogging. Tonight was my first jog and I just ran round the block - 4 mins. My son said he wanted to come with me and I said he could. He kept up with me (a steady pace), in fact he wanted to go faster but I told him to slow down. He is big and energetic for his age but I worry at his age jogging might be dangerous for him? I will go again tomorrow on the same run and he said he want to come. I dont mind him coming but if it dangerous for him to do so at his age I wont have him come out with me. Im going to do this 3 times this week, 5 times next, every day the week after and then lengthen the distance as my endurance builds up. What do you think?