[kierae0608 (OP)]

How can i tell if my aquatic frog is pregnant. ?

[CliffordK]

Your frog can't actually be pregnant.

Frogs reproduce by the female frog releasing eggs into the water.  The male frog can mount the female and fertilize the eggs as she releases the eggs. 

Here is a brief discussion about frog reproduction.  You may be able to find the jelly-like eggs in in the frog habitat, and should see the tadpoles growing if the eggs are actually fertilized.

Here are some notes about recognizing male and female African Dwarf Frogs.  One of the photos shows the female African dwarf frog carrying eggs (but, of course not fertilized).