I completely understand how stressful this is, especially when you're dealing with both the SCH and now the cervix length concern. The good news is your doctor is on top of it with the Utrogestan, and spotting during treatment is actually quite common as things settle down, especially if it's just a wipe or two of red blood rather than continuous bleeding. I'd say keep a note of the pattern (like how often it happens, what colour, how long) and bring that to your next scan or check-in rather than rushing in for every episode, unless it suddenly becomes heavier or different from what you're seeing now. For now, try to rest when you can and follow your doctor's plan with the medication. Sending you strength through this worrying time.