Signs of Baby Concussion?

Okay so DD is mobile now, flipping all around, always on the go, not yet crawling but she gets from point A to point B.
Anyway the other day, SO was changing her and she wiggled right off the bed (we usually change her on the bed on her changing pad) and fell off. It happened too quickly for him to react. THANKFULLY there were pillows and she fell on the pillows and just bounced on the floor, but she hit her head and cried. Mostly I think it scared her, but it terrified us.
She recovered quickly and seemed fine. BUT, I was wondering, when should I worry? I've asked the nurse practioner at our last visit ( this hadn't happened yet) and she simply just told me "if a baby gets a bump, that's actually a good sign. Worry if she seems lethargic." I guess this answer sufficed at the time, before she had actually fallen or took a spill..
So, this is a dumb question probably, but what, if any, are signs I need to look for in case something IS wrong if she hits her head? I just hate the thought of thinking she's okay and her not being okay.
I'm going to ask her Doctor at her next appointment, but in the mean time, do any of you mommies know what signs or symptoms of there being something wrong are?
This is really just a precaution question, but I'd like some other input from mommies?

Sometimes there aren't any signs at all. But watch for lethargy and vomiting. Also, keep an eye on the pupils. They should be round, equal and reactive to light. Babies are pretty resilient, though.

Lethargic, vomiting, any change in her pupils. You can check if the bother react with a flashlight. Always eased my mind when DS would bump his head.

Throwing up is a sign. Breathing, pupils won't dilate, lethargic.

If they are tired because it's nap time or bed time, it's fine. And don't worry about keeping them awake. Regardless if they are asleep or awake, if something is going to happen... it will happen. But your daughter sounds fine. My son flipped off the table when he was four/five months... It was my stupid brother's fault and trust me, he's never held any of my babies since. We caught him mid air. Scared the Smurf out of me.

Quoting ♥GarciaMommy:" Throwing up is a sign. Breathing, pupils won't dilate, lethargic. If they are tired because it's nap ... [snip!] ... stupid brother's fault and trust me, he's never held any of my babies since. We caught him mid air. Scared the Smurf out of me."

Oh man, I guess! It's terrifying. I felt like such a bad parent.
We were just commenting on how she hadn't taken a nasty spill and boom, it happened. And she WAS tired but I couldn't decipher if it was because she needed to nap or not because she's currently switching up her schedule on us. Freaked me out.
But good to know, ladies! Thank you.