2000 Buick Lesabre car pulling

HI,
i started to nitice that my car would "pull" suddenly starting at about 65mph it feels like thears strong wind but thears no wind I had low air in my tires (aired them all up) still happens my uncle says im nuts but I know for sure somethings different its like thears a 2in play in the stearing wheel all suspention peices seem stitt and sound I dont know whear to look next if anyone has any idea please let me know thank you

michael