"Overwhelmed with your wishes and blessings .. 2843 new tweets in half an hour! Thank you all ! Your affection and love is so touching," posted Big B on Twitter.
Aishwarya and Amitabh's son Abhishek got married in 2007 after the release of their film "Guru".
On Tuesday night, Amitabh posted on Twitter: "NEWS NEWS NEWS !! I AM GOING TO BECOME A GRANDFATHER... AISHWARYA EXPECTING... SO HAPPY AND THRILLED,"
In no time, congratulatory messages poured in on the microblogging site and Priyanka Chopra was one of the first few who wished the Bachchans, tweeting: "Awesome news!! lets make way for the legacy to go forward."
R. Madhavan posted: "ohhh.. Sooooo Happy for you sir.. The legend continues..Love to the whole family."
Dia Mirza posted: "Congratulations!!! Wonderful wonderful news."
Koel Purie said: "Wow!! That is wonderful news. AB and Ash will hv beautiful children no doubt."
Sophie Chaudhary posted: "Wow!! Congrats soon to be dadaji! Thrilled 4 @juniorbachchan & Ash! Much love n happiness to u all!!."
Riteish Deshmukh posted: "Congratttttuuulationnnnnnssssssssssss- superrrrr superrrrrr happppppyyyyyyyyyyyyyyy."
Actor Rana Daggubati, who has worked with Abhishek, in "Dum Maaro Dum" wished him and posted: "@juniorbachchan is soon to be Daddy Bachchan. Congrats and lots of love."
Genelia D'souza too congratulated Abhishek, saying "congratulations ab, super, super happy 4 Aish n u, one things 4 sure, d kid vl b one hell of a good lookin kid congrats agn."
And the 68-year-old would be granpa made sure he thanked them all for wishing the family.
"No words to express my gratitude to all those that wish us on the coming of a new born in the family .. I am humbled, honored, happy," wrote Big B.
Amitabh Bachchan declares on twitter that his bahu Aishwarya Rai is pregnant!
