they might get pregnant at least once or twice after having babies.
It is very possible that you did not buy two girl gerbils. Rodents are very often misidentified at a pet store. I thought I had two female hamsters a couple years ago but as it turns out, one was actually male. They had babies and we had to take the male back to the store (along with the babies). Be careful; sometimes the males eat their young! Also, pet store often sell pregnant rodents. One of the females could have been pregnant before.
Dreaming that you are pregnant and you have had miscarriages is not a sign or pointer to future troubles, as you can still have babies.
because they body might not be able to produce babies
Gerbils can have a litter about every 5 weeks. Gerbils mate right after the birth of a litter, and the mother can prolong the pregnancy to up to 40 days if she is nursing. A gerbil will produce about 4-5 pups on average per litter, but can have up to 12! With about 10 litters per year with no break, that means about 50 gerbil pups a year! They are rather prolific breeders. :]
No you do not need to be pregnant.
frequently.
Once a month
No, mice often have up to 3-4 babies at one time
No, the majority of women with BV have babies who are born on time and with normal birth weight. There are some studies that show that BV increases the chances of prematurity and low birth weight.
It can hurt the development of the baby. Babies to smoking moms are often smaller at birth and develop slower than babies from non-smoking moms.
Gerbils may bite occasionally, especially if they feel threatened or scared. However, with proper handling and socialization, most gerbils can be friendly and gentle pets. It's important to approach gerbils calmly and build trust with them to minimize the chances of being bitten.
I think gerbils will more often because they are more curious than hamsters.