Non-stress tests?

My doctor said I will start them around 32 weeks and do then weekly up until 35 week and then I'll start bi-weekly... I didn't think anything of it, until I just read on my app that non-stress tests are usually saved for high risk pregnancies. He has never told me I'm high risk, but I was wondering why he is going to have me do so many.. Did anyone else do a lot of these tests? Were you high risk?