Yes I've heard from tons of people those can make you bleed - especially in early pregnancy. I had one just on Tuesday at 20+3 but didn't have bleeding - mostly because it's 2nd tri and she only checked my cervix so was very gentle. In 1st tri scans they check your ovaries and all over your uterus, so they have to be more rough and that much jostling can make your cervix bleed.
The bleeding should stop soon, or turn brown/rust coloured as it becomes old blood.
It's so, so common, and you know why you're bleeding. But big hugs, bleeding during pregnancy is the worst!!