I have felt pregnant for a couple months, but have been getting periods...otc pregnancy tests were negative...recently I have been having unexplained lower back pain, and Sunday I felt what resembled a few good kicks to my ribs from the inside for a couple hours, and a few smaller movements since then... I have two children, ages 10 and 13 so I have pregnancy experience :) What could be going on here? Btw I am 37 years old