Schizoaffective or bipolar?

My grandfather was schizo affective and had bipolar from what my mother says. And I was just wondering that since I was diagnosed with bipolar and show signs of a psychotic disorder does that make be schizo affective? I mean I hear voices (usually at night) and I feel things crawling on me when there's nothing there. I also have delusions about my mental diagnosis which is why I keep asking these questions on yahoo answers and compulsively looking up all these symptoms and symptom checkers on google and another thing there are things that I cannot tell if they are real or not like I will feel a hand rest on my back and I turn around and there's nobody there in the room!