2 new guppies- starting over

Last Sunday I got 2 new guppies to replace my old ones. They're looking good & healthy so hopefully they'll be ok. The female is due to have fry but I'm not sure when seeing as I dont know when she fell pregnant. Shes a little bit fat but her gravid spot isn't very dark. Is there any way of telling whe she will give birth?
Thanx

 

how many guppy's do you have and what is the male it female ratio

 

There are now 3 Guppies in that tank. It's 2 females to one male.

 

Generally I heard that it is best to have about three or more females per each male but I think you should hopefully be at a safe number.

 

I bred them (only later, the whole tank cought ich)and i had 2 females and 2 males, only i heard it was best to have at least 2 females to every male. i simply couldn't find a petstore that didn't sell them in either male and female pairs or a single male.

 

what size tank do you have if you have then room i would add one more female the reason being is to releave stress because the male in allways wanting to breed so he will chase them around 3 to 1 alot least stress when bred guppy's i start with 5-1 and i ended up with to many guppy's to handle