What Causes Pain In Groin Area And Tail Bone?

Hello,I am a 32 year old male. Over a week ago I assumed I had my first kidney stone. I had pain under my left ribs and the left side of my abdomen. After three days the pain shifted to my groin areas. It didn t burn a lot urinating but I did feel a difference. I was also constipated those three days (i usually go once or twice a day). I had become dehydrated the previous week and thought this was the cause. I never saw the stone pass but on day 7 the burning and sharp pains went away.But now after 14 days I have a constant pains in my groin area. The pain feels dull and coming from inside of me. The pain also jumps around sometimes it ll be on the left side, sometimes on the right, some times in my left buttocks, and or my tail bone. The pain isn t trigger my any movements it s just constant. Weak in the morning almost non existent but it feels heavier by bed time. Also it feels like my lower abs are tightening up when i goto bed.I currently don t have a doctor. Actually I haven t had one since leaving the army 10 years ago. I am unsure of what type of doctor to see. Do I see a GP or go straight to a specialist?