My Hamster wont get pregnant.

Question
QUESTION: I wrote to you about my two hamsters, that one of them was running around madly, building a huge nest, gaining weight, hiding food in her nest.
It's now been 20 days. WELL over the gestation time. The problem is, she won't mate again with my other hamster, I know her oestrus day from mating her previous times, but she still won't mate, just fight with him.
I have checked their sexes, both different. I don't know why I did, because I've mated her with him before, but just in case.
She's still gaining weight. I'm starting to get worried and I really want to know what is wrong with her.

ANSWER: Hi Annie,

    This is usually an indication of phantom pregnancy. If the female does not show signs of giving birth this is normally not a great worry as the babies will be re-absorbed into the bloodstream causing no harm to the female. However, if a female seems to be having difficulty giving birth or seems sick then veterinary advice should be sought immediately.
    How old is your female and how many litters has she had? Is she a type of Syrain hamster?


---------- FOLLOW-UP ----------

QUESTION: She is about 18/19 weeks and this would be her first litter.
She is definitely a Syrian as the pet shop we bought her from had only Syrian Hamsters in at the time.

Answer
Hi Annie,

     I am guessing this is a phantom pregnancy. If she does not thin out within the next couple of days, you may want to consult with a vet.
     If you have anymore questions, please write again.

Thanks again for writing and best of luck.