Just bought a 09 Nissan Altima, and my power steering fluid is leaking

So I bought a used Altima a week ago, cash, and the car runs well except for the power steering fluid leak which started about 2 days after I had the car. I noticed it when my steering wheel started becoming hard to turn and I could hear whining every time I would turn it, so I went and bought power steering fluid for it and put some in, and it was working just fine. I get home then the next morning the steering wheel is hard to turn again, I check the reservoir and the fluid is almost empty, and it's also a milky pink color. I did research the pink fluid and learned that it could be water/air getting into the system and that I should do a flush, however, would a flush also solve the leaking issue? I can also hear the pump when I initially start the car, and the steering wheel sometimes jerks while turning. I'd like to get an opinion on it before I take it to a mechanic to take a proper look at it.