Upper back pain could I be prego?

lupita
Okay so after I took a shower yesterday i felt my back with some pain not sure If because maybe the window was open and maybe I got air, today I woke up with more pain in my upper back , at times I get cold and hot then I feel my head kinda light headed does anyone know what it could be. I had unprotected sex but he didn't nut in me so I hope it's not that..