Miscarriage???

Hi :)
I am not sure if I just had a weird period or if I might have had a very early miscarriage. My period was four days late and then when I did have it, it was three days long and I passed a couple small clots....which I have never done with a normal period. So, I am not quite sure what to do. Could this even happen with a normal pregnancy and the baby be okay? (If I am pregnant)