You'll know you are ADHD (in addition to autism) if you consult a doctor and get diagnosed (or not).
If you're seeing that one condition dictates you must have the other, I'd assume you're dealing with cognitive bias. There are plenty of people in the world who have one without the other and clearly no indication of the other.
No sense in being "worried about ADHD" just for the sake of it. If you have ADHD symptoms that are hindering you in life, get professional help. If you are not hindered by ADHD symptoms, stop worrying about it? I understand that might be hard if you are obsessing over it, just saying there is no point to it if you don't actually have the symptoms.