I read your question carefully and I am sorry about your concern. First regarding what your mother has been saying of course there is no medical basis for that and if you haven t had sexual intercourse yet that is out of the question. Now if you get up at 5 pm in the morning then it is natural that you will have to go to sleep earlier. You do not specify the exact time you go to sleep, so can t say whether it s too early, but generally while the ideal sleep time is about 8 hours at your age, sleeping times of up to 10 hours are considered normal as well, no reason to worry. I hope to have been of help.