Yes, I actually had quite a bit of blood on mine but they said it was fine because it hadn't spread beyond the dressing.
I had a bit of blood on mine the evening of my csection- in the hospital they drew a line around the blood spot on the bandage and then kept checking that it didn’t expand beyond that line, as a way of checking that it wasn’t still bleeding. Def ask a midwife if you have any concerns :)
It’s normal to have some blood on there yes, not an enormous amount I’d imagine however, but a few blood spots or what they call ‘strike through’ can be normal. I had a few small patches of blood both times and had no issues. If you’re concerned however I’d ask the midwife to take a look!