bloody mucus on stool sometimes- Emergency?

So we have had Bub for 4 months now, she adopted us by giving birth on our patio, and at first she had really bad loose stools. We figured out (with some recommendations over the phone from the vet) that her tummy has trouble with poultry products. We only feed her foods that have very little to no poultry in the ingredients list and her stool has been stinky but normal (as far as we can tell) for several months.... Now all of a sudden this week we are noticing bloody mucus on top of her stool twice. Today she pooped on the bathroom rug ( we've never had litter box issues before) and it had some blood on top.  She has been acting completely normal with eating playing and sleeping otherwise. We are set to leave tomorrow morning for a few days for the holiday, We have a sitter visiting a few times daily but... QUESTION: Should we postpone our trip and get her to the vet ASAP?or can it wait 3 days? and our follow up question: Does anyone have ideas? I have read about constipation on this site and it seems to match the symptoms... but I am worried about it being something worse... and we really can't afford any medical issues for her.... We would probably have to find her a new owner if she needs anything that will cost much since we are in a rough situation right now  

Thank you all for your responses.

Blood on the stool is common with constipation.  Is it small and hard stool as well?  Has she been checked for all the parasites?  Is she fed wet food?  Constipation can often be prevented by feeding wet food.

Bub gets about 3-4 oz of wet food a day along with free feeding of dry food (with two of her kittens). She was a bag of bones and only weighed 4 lbs when she had the kittens but now that she is starting to get a bit wide at 9 lbs so we are starting to cut them all back on the free feeding.  We had them all in to the vet in early October, they all got shots and de-wormer and Bub got fixed. They all drink quite a bit of water... we re- fill their water dish s few times a day. 

She had blood on her stool when she had diarrhea really bad... but it is not diarrhea this time so we are confused.... that and she is acting perfectly normal. Also, before she wasn't cleaning herself or playing much.

Do you think we should feed her more wet? I also read a bunch about miralax?

You can try the Miralax.  Start with 1/8 teaspoon twice a day and adjust the dosage.  You want enough to keep her regular but not have diarrhea.  It is tasteless so it can be mixed with her wet food.  I would go ahead and give her two wet meals a day and hopefully be able to get her completely off the kibble once the kittens either no longer need the extra food or they go to their forever home.  

The kitties are in their forever home we couldn't give two of them away, they melted our hearts. I'll look into the kitten's nutritional needs and we will try to switch her to wet food completely. It is tough with her poultry issues... we can't afford expensive stuff... at least not right now. We are torn about keeping her or trying to find her a new forever home with a bigger bank account We will talk to the vet about the miralax too... we will take her in later this week or early next week depending on when the vet will see us. 

Is she still eating, drinking and acting normally?  Blood in the stool is alarming and should be checked out by the vet ASAP but I don't think it is an emergency unless she isn't eating/drinking or acting normal.

I apologize for the delay in answering. She has been acting normally, but now we are noticing that her belly is really wide... it almost looks like she is pregnant again... but she was fixed in October. We also haven't noticed any more blood  this week. We are just going to have to take her to the vet... and cross our fingers that everything is okay.

She may have worms.  That can cause  wide belly.  Or she could just be gaining post spay weight (which happens because it changes their metabolism). 

We had her dewormed just before we had her fixed in October... and she has not been outside since then, could it still be worms?  At first we though it was just weight gain.... we had been trying to get her to gain weight because she weighed only 4 lbs after she had the kittens, but it just looks so odd the way it is all in her very wide belly. She is up to 8 or 9 lbs, although we haven't weighed her for a few weeks now so it could be more. 

  I guess I am just nervous that is is a blockage  or something else that will require expensive surgery. gulp.

Just to follow up on this ( because nothing is worse than finding thread that you think might help only to find no conclusion)-

  We weighed Bub shortly after my last post and she was just shy of 12 lbs!! We switched her to mostly wet food and we add water so she gets around 5 oz of wet food mixed with 5 oz of water split between two meals and a small scoop of dry at bedtime (we no longer free feed her, but leave dry food where only the kittens can reach).  We also switched her back to the old litter we were using since she wouldn't dig in the box any more (she would just hop in, squat, and hop out). She is now down to around 10 lbs with much more normal looking poop. She is also more regular in terms of timing too. My non-professional opinion is that it was constipation as a result of not enough water,  a dislike of the litter,  and maybe a few hair ties. And thankfully it cleared up all on its own!