What happened so far?

I live in the US and so far I saw Simran and Abhi getting married, with Aastha still showing attitude during the wedding. I saw some preview showing a lady coming back...but I don't really know who it is...

What's going on in India? I think they're 3 weeks ahead or something...

the woman they showed during the preview was Kiran. She is the model whom Abhi fell for while Simran was pregnant with Sia, had an affair with, and unofficially married. She left him for another man (Anil Shourie) later on.