Never hurts to have it checked out. Better safe than sorry.
How often have you come off of this horse? Every time you hit the ground is a potential for life threatening injuries. Hate to be so pessimistic - but I am right now recovering from back surgery. 3 weeks ago I was in an ICU which bites. Not necessarily from coming off of my horse but it dang sure didn't help my issue. I pitched over my horse last year. He didn't throw me. Landed flat on my back.
Even as young as you are - you will one day NOT be young and all of the stuff you do to yourself NOW will come back to haunt you!
I am looking at maybe just MAYBE being able to ride by July and my horse is a total sweetheart.
If he is spooky and turns and bucks he doesn't need to be on the trails yet. More ground work and lots of wet saddle pads. Hope it gets better but if your headache isn't better soon tell your mom. A trip to the ER might be in your best interest.