Most neighbourhoods in Ankara have at least one TIp Merkezi. These are private clinics that offer a range of health services from doctor visits to blood tests and lab work. The prices are displayed clearly and are usually reasonable depending on the area of the city you are in. For example, a basic blood test might be about twenty lira. Walk ins are accepted; bring your ID.
If you see a sign for TIp Merkezi in your neighbourhood, make a mental note. These clinics can be less intimidating and overwhelming than the big hospitals and tend to be open until 12 at night. To help locate a TIp Merkezi near you, type TIp Merkezi+Ankara into google. Although the sites that come up will be in Turkish, google will display the different clinics on a map for you.