Ay oo, normal yan lalo na kung nag-carry ka ng baby or kids throughout the day, nakakaramdam ako ng ganyan din, especially pag stressed o pag mahaba ang standing, it comes and goes lang talaga! But kung tumatagal na or tumataas ang intensity, better check with your doctor para ma-rule out anything serious, kasi back pain can be tricky sometimes at mas okay na ma-assess ng professional.