Pregnant Teddy Bear Hamster

Question
Hi, We bought 2 TB hamsters for our boys 2 weeks ago and was going for 2 males (our M is 11wks now and F is 10wks).  Well, low and behold 4 days after we purchsed them they were going at it one night (not too impressed).  I found a site that mentioned that the female will come into heat every 4 days, and just as predicted, 4 days later they were going at it again.  Well then 4 days after this, and watching every night as I play and spend some time with them, they have not done the deed since.  Does this mean that the female is indeed preggers and do I start to count the days from the last day I saw them doing the deed?  How many days is the gestation? I think the rest of the site has answered my many questions I would have, but after scrolling through pages of questions I still cant find these answers.  

I separated them today into their own cages.

Thanks in Advance!

Answer
Hi Sage,

    It is very possible she could be pregnant. The gestation period is 16 days. Yes, you count the days from the last day you saw them mating.
    The females sides will poof out (get fat) about 10 days into the pregnancy.
    My only concern is her age. The ideal age for breeding a female is 4 months (I understand that you thought you had to males and this was not planned, just giving you a heads up). Ones bred younger have a higher chance of eating or abandoning the babies and having a hard time giving birth.
    If you have anymore questions, please write again.

Thank you for writing and best of luck!