Nosebleed

Hi , I am a 15 year old male. I have never had nosebleeds before and they and I started to get them when I started to sleep in the basement. My bed/couch was kind of near the machine that produced all the heat that went all over the house. I have been reading on the internet about nosebleeds and then I saw it say that a nosebleed could be a sign of a brain tumor. This was only about a month ago. I have always felt fine even when I had the nosebleeds. I just never thought anything about it. I would wake up in the middle of the night with a nosebleed , it wouldent last long. Never causes me any trouble. But after I read that thing about nosebleeds and brain tumors I became kinda paranoid. Then I went back and read in detail about brain tumors and came to the conclusion on my own that I did not have a brain tumor because I did not have any of the other symptoms. Then I started watching myself very carefully , actually looking for signs of a brain tumor. I dont know if its because of movies and picture and things iv seen. But if I had a headache or so I would get kinda worried. I feel perfectly fine and in great health when im not thinking about it , I think I might have some kind of anxiety or something. A few weeks ago in pe I got smacked hard in the arm with a basketball and also got ran into in that same arm. I had a tingly pain today in my left arm which was the arm that got hit and everything , I dont have any discoordination with it or anything. I just kinda got a little throbby feeling up near the bicep and near my thumb but that went away in like a minute. So I dont know if subcontiously im kinda paranoid about it so I think im getting symptoms which are nothing at all. I mean , I used to get headaches before this and never even thought twice about it , I was in a head on head collision before in school tho and I went for a head xray , I was fine and had just a small concussion. Are these just normal after effects of a collision like that? Oh yeah , and for the nosebleed thing , it was like , maybe twice a month or I might not get it sometimes. I have read about people with exact symptoms as mine with the nosebleeds and its just to get a humidifier for my room and keep my nasal area moist. When I have a nosebleed its more near the front of my left nostril. It has never went down my throat or anything, so basicly , am I all right and im just kinda paranoid :) , or is there something wrong with me? Other times im just feeling fine. Its just kinda when I think about it .