blood in stool can be the result of many things...and it may not even be real blood. Have you fed anything 'red' to your dragon lately? Natural red food dyes found in colored pellets (though you didn't mention feeding any pellets) or red flower petals, peppers, strawberries and other red fruits...can turn the stool red and in combination with the usual 'brown' of stool, can look like blood.
If the stool is very hard, constipation could have caused a tear which bled. Parasites can also cause bleeding if they have a heavy load of parasites. If constipated, you need to get more fluids in your dragons. Normal dragon poop should be formed but not hard to 'squish' when you pick it up in papertowels to throw out. The white part, the urate, is typically much more firmer but can have a jelly like consistency. Also, if your dragon is well hydrated, should be a good amount of fluid expelled along with the stool.
If its alot of blood then I would take your dragon to a vet immediately, regular or not. If she's really bleeding out of her vent even between bowel movements, this indicates a tear which could cause her to bleed to death or get infected. If just a small trace of blood...you can wait till your regular vet returns (as long as he's back and you can get in to see him within a week) and take a fresh stool sample to him, to check for parasites.
Have you been breeding your dragon? Sometimes copulation can cause a little blood in the stool though this usually should only happen in the one stool sample unless you are keeping them together so there are multiple copulations spread over many days. Even then, I would separate her from the male and see if there is more trace amounts of blood in her next stool.
-----
PHLdyPayne