How do you know if you’ve had a miscarriage? I’ve never experienced one, but I’m wondering if I pregnant and didn’t know it and maybe had a miscarriage. My period has been on schedule/on track for several years now, but it was several weeks late this month. It finally came, or I thought. It came on very suddenly and was heavy right from the start. Usually it starts out very slow and is very light. The cycle was shorter than usual too. Now I have been experiencing terrible cramps in my lower abdomen and lower back these past two days, even after my period has completely stopped. I am worried that I might have had a miscarriage without knowing it!