Breeding and going into heat

Question
I tried to breed my female yorkie on May 9th and 12th. She did not get pregnant and I want to try again. I just noticed this week that she is spotting . Is it possible that she is in heat again? Her vulva is swollen and her nipples as well.  How can I tell how far along she is in the heat cycle or if even if she is in heat? She is 5.5 lbs and tuned 4 years old on July 7th.

Answer
Deborah,

Anything is possible but unless she has a history of going into heat only four months after a previous heat I would not think that is what is going on.  It sounds like a hormonal problem to me.  In order to better access the problem I would need more information than you have provided.  Questions like, how much time has she typically gone between heats in the past?  Do you know why she didn't get pregnant?  Have you bred her before and if so did she get pregnant?  What day of the heat cycle did you breed her on?  

I think that you should take her to the vet to determine if she is really in heat or if there is a hormonal problem going on.  It is always better to err on the side of caution.