7 month old fell down the stairs, would like opinions.?

I had the kids upstairs, I have 4 in total. Oldest is 6 and the youngest is 7 months. My little man has been crawling since 6 months old. Well I put up the gate so he couldn't go down the stairs. I went into the laundry room to change the loads and while I was in there my 4 year old decided he was going to go downstairs. He pulled the gate down and Thomas (my baby) followed him. I hear his little scream and run out and pick him up quickly. I first focus on calming him down, which didn't take more then 5 min if that. I then checked his eyes, making sure they were the same and were dilating like they should, I took him out side and they got smaller so went back inside and they went bigger. It was his morning breakfast time but since he fell I just decided to let him have a bottle instead of food because it is more soothing for him. He ate it just fine and didn't throw any of it up. By the time he was done with his bottle he was up crawling and ready to go play again. But also by this time 3 bumps had formed on his head, so I was still really worried. However I let him down anyhow and he wasn't sleepy he just wanted to play with the others. He was smiling and acting completely normal. That happened at nine. At 11 was nap time, he did get fussy right before that but he always does so that isn't unusual. He took an hour nap and then was ready to get up and play. Between then and 2 in the afternoon I fed him a meal and he played and was completely acting normal like nothing had happened to him. Still had three bumps on his head and a couple little bruises maybe the size of a nickle. He went down for his nap at 2 and slept just fine. Woke up around 3:30. After which he played a bit, I had to run some errands so he spent some time in the van and also was fed dinner. Then at 8 he was put to bed, all my kids go to bed at that time and he has been since about 5 months. Every night the same so perfectly normal. So besides a huge fall this morning he has had a normal day. And despite it he has acted just fine. I called the doctor but didn't take him in as, like I said he was acting just fine and perfectly normal. And the doctor also just told me to watch for signs, which I was already aware of watching for.

So my question is, what would you have done in this situation. Please understand I am a mother of 4 so if I had had any inclination that he was hurt really bad i would have taken him in instantly. Most people rush their kids the the ER and there isn't really anything that can be done, falls and bumps on the head being a major one that can't really be treated. Also he isn't the first kid to fall down the stairs at one point or the other. However he is the youngest, always has to do everything earlier then the rest. He was rolling onto his tummy at 2 weeks of age.