I need Help!!!!!!!!

Question
I have two gerbils, I got them about 2 weeks ago, and i hold them but i can't tell if they are male or female. I think one of them might be pregnant, it keeps getting bigger. i looked on the internet to see pictures of pregnant gerbils and it's not as big as the ones i've seen. i can't find an answer any where. i've tried to pick them up and look to see what sex they are but they get scared and try to bit. If you can help me i would be so happy. thank you ,
Jessica

Answer
Here's a link to tell male from female...
http://agsgerbils.org/Gerbil_Care_Handbook/breeding.html#separating
If she's pregnant then she'll have pups within a week. Gerbils fatten up at 18 days and give birth at 24. Make sure you don't have your gerbils on cedar or pine bedding ESPECIALLY if she is pregnant. Put them on corn cob or carefresh.

Ashley