Why did my dog stop going into heat?

 
Why did my dog stop going into heat?
I have a 6 year old dog, and we have had problems with her having puppies, but we never had enough money to get her fixed. She hasn't gone into heat for a little over a year. She is a mutt, I think a kind of terrior. Is something wrong with her?
answer:
Possibly. Visit a veterinarian to find out what's going on and schedule her spay.
What do you mean you have had problems with her having puppies. I do hope you don't mean that you deliberately bred your mutt.

And at 6 yrs old she is too old to try for pups now anyway, so it will be good if she doesn't come into heat anymore.
find someone who will spay her for a low cost, or save up for it... it's not fair to her... not trying to be mean. yeah go to a vet or get one on the phone to try and see what might be wrong.
Call your local shelter they might spay her at a discounted rate.