I had spinal meningitis at 18 months, and neurological testing at age 4 only indicated adhd, can it give you a susceptibility to migraines and/or pain?

Possible: It is not impossible that the initial insult to your brain with the infection could have triggered the migraine headache disease process. It would be difficult to prove. Many migraine sufferers do not know the real cause of their headache, but know how to treat it. And in some people, the cause can be multifactorial. Finding what triggers a migraine can be almost curative.

Maybe: If you had meningitis at 18 months & have a negative family history for adhd, then you may have secondary adhd, caused by the infection. Both kinds of adhd have a high incidence of migraine as does post-infectious encephalopathy. Regardless of the cause, migraine is treated the same. Check your family history for migraine, it is highly heritable. Learn the triggers for migraine & avoid them.