@woahhh if you’re not in pain it’s likely nothing, it’s actually quite difficult for people to check their strings themselves.
The reason why I’m saying it’s likely nothing is that if your uterus was perforated you’d be in a fair amount of pain.
The blood could have just been a coincidence due to spotting or your period starting.
However, if you think this is worth checking out do so, but I think that waiting until Friday sounds reasonable