Over the past few days I have been longboarding all day for a week and a half, when suddenly my tailbone and lower spine have been aching non stop, for the first few days it was only after id gotten off my board that it had started hurting, but today all it's done is linger in pain, it's swollen and I can barley lay down on my back. I hadn't fallen on my back recently nor have I twisted it but it continues to ache. It usually hurts when I bend my back or put too much weight on it. Is it necessary to see a doctor or chiropractor? Also I'm 15 years old so I don't think it's because of Old age.