new regular bp female - might be pregnant - fluid

hi i got a new regular female who was kept with a pastel male, and though she probably isn't the best size to be bred, i think she's pregnant.

how do i tell? i've never had a pregnant bp. the thing that concerns me is the presence of a lot of fluid by her vent. Is that normal or is she sick?

A pic would help a lot, as would a close estimate of her size.
If the body near the vent is swollen and feels like a water balloon, then she is probably stopped up and can't pee/poo.
Soaking in warm water sometimes helps this.