I think my cat has worms, but I'm not sure

[Ash_A]

I have a cat, well he's really a kitten. He's about 6 months old. I adopted Kaden when he was roughly one month old, and due to the fact that there is no veterinarian in my town, sadly I haven't had him examined yet. - Yes, I know this is irresponsible, and now that I think he has worms, I feel horrible.

He's a very active kitten, and quite large. He's always eaten like a horse, and I've just assumed that's why his stomach is the size it is. However due to recent discusion about my friend's dog having worms, I realized that his stomach feels bloated, not at all soft or squishy like fat.

If I press my ear to his stomach after he's eaten, I can hear noises that bring to mind the snap crackle and pop of rice crispies. I don't know if this is him digesting, or if it's another sign of worms.

I guess the real questions here are

1) do you think he has worms

2) if so, and he's had them this long, have they harmed him?

and 3) is it okay for me to purchase over the counter dewormers, or do I need to take him out of town to see a vet?

to anyone who actually reads this, thank you for the time and advice.