How common is spotting in pregnancy?

Helen
Hiya all you lovely baby growers! So I have a question. How many of you have experienced spotting (small amount of brown kind) during pregnancy and all turned out fine?
I have a early scan booked in for tomorrow to double check all is ok but just trying to calm myself/prepare myself about going so wondered if you could tell me. Is there a cause? Could it be something I'm not expecting like infection. I know it might be early signs of MC but also that it might not be...any pearls of wisdom from you gorgeous lot would mean the world to me. Peace and love 😍