I think I might have OCD?

Sorry if this gets a little long. i was just reading about it, and I think I MIGHT have it. i read that some of the symptoms are...well i dont really know how to word it, so here: Other obsessions concern the possibility that someone or something other than oneself—such as God, the Devil, or disease—will harm either the sufferer or the people or things that the sufferer cares about. i always am thinking that if i dont do certain things, that something bad will happen to me or my family, or my friends. i am always thinking about it, and the longer i stop doing these things, the more i feel like something bad is going to happen. also, there are sometimes just other things i do that make me think i might have it. for example, every time i do anything, i always have to do it either 4 or 8 times. like, if i flip a light switch. i have to do it 4 or 8 times (most of the time...sometimes i dont). or sometimes when i'm writing, even after i finish writing a letter or word, i always have to go over that letter or word a whole bunch of times. or when i'm typing, sometimes after i hit a certain key, i have to backspace it a certain number of times, and keep typing it until it like...feels right. i could keep going on with examples, but whatever. do you think i have OCD? Thanks.