Why do my car pull towards one side while.

That's what you pay a suspension and alignment specialist to figure out. He is going to ask you how long it has been doing that, if this is something new that just started, what recent repairs were done, does it pull all the time or just under certain conditions, and a lot of other stuff you didn't include in your description. Based on those answers, the list of possibilities include a tire pull, a broken belt in a tire, a worn control arm bushing, an alignment adjustment slipped, sagged front coil springs, a sticking brake caliper, low tire pressure, mismatched tires, contaminated brake fluid, ... Where would you like to start?