Did you have headache after walking / exercising for too long before being diagnosed?

I will have sleep study in like 2 months and I'm wondering if it's sleep apnea related or not , basically if I exercise too much let's say running or swimming / playing sports like basketball etc. anything that requires you to move alot then after that I get massive headache in my forehead area.

It does not happen if I just lift weights , it still happens if I walk long distance let's say 3+ miles walk.

I have high red blood cells levels usually around 6 , never went over 6.2 tho.