I am saying Tannu planned very well because she didn't revenge on Pragya for the modelling thing so far.. other than this pregnancy. Normally Tannu does something everytime Pragya wins.. Like cutting Abhi's shirt, guitar etc..
This time, Tannu acted calm.. because she had this BIG plan perhaps.
I thought Pragya taking Tannu's position as model and then Abhi even declaring love for Pragya (although it was for act, it did look sincere from his side to Tannu).. was the last straw that drove Tannu to this?