Ah, your poor doggie. So, you have control at the vet. You can take her in to be checked. Talk about what is going on and what 'could' be wrong and then decide from there. Then you are out a vet visit which is I think around 35 dollars most places. You can decide if you want to do any testing if they recommend it. Your dog could simply have a little hormonal issue! (I can relate, so do I!) ha) So, take her in and get her checked and then decide. Don't assume it's 'the end' and you have to consider euthanizing her. Let me know what the vet says!
She does need to see the vet urgently. Please do find a way to take her there, even if it means giving up something else you need or would like to have.
If you don't have much money, are on benefits or a low earner, there nay be charitable help or financial help of some kind available
Many vets won't do this, especially if they are dealing with a new client/patient, but you don't know unless you ask....that is ask if a payment plan is available, as you are on low income but need to help your dog.
Investigate overdraft facilities at your bank, and what the charges would be for an arranged overdraft. It may not be as bad as you think! And may release quite a good amount of cash within a day!
But please get your dog some help. This bleeding is not normal.