I am 13 years old and my stomach has been feeling weird and different lately. I have all the symptoms of pregnancy such as gas, constipation , and I've been feeling light headed everytime I get up. I also feel very tired. My stomach looks bigger too, there's like a little bump at the bottom. I have mastubated many many times. By humping a pillow. The thing is , I never did anything with a guy. I never even kissed a guy. But I still fear that somehow sperm got into my vagina. Is it possible in any way that I can be pregnant?