Does this mean i have a disease? please help im kinda scared..?

so the other day me and my sister wanted to see if it was true that your armspan is the same as your height and it turns out that my arm span is about 5 inches taller. Im 5'6" and im 15 and my arm span is 5'11" (my sister and i used a tape measure the other day so it might not be exactly 5 inches taller but still it is significantly taller than my height) i play volleyball so i guess its a good thing to have long arms but i have long legs too (so my friends say) and i have flat feet and long skinny fingers and toes so i thought that this just meant that i still have some growing to do but then i searched it online and this marfan syndrome came up and said how its genetic and causes heart problems. Most kids who have it though have lazy eyes and are really tall and weird chests but i dont have any of that but everything else they named i had so i dont know.. do you think i have this disease? it said that people who have it shouldn't do sports and i do lots of sports so im scared that that might hurt me if i really do have marfan. do you think i'm just still gonna grow or do i have marfan? please help