Mum-to-be Frankie is due to give birth to her first child next month but she has been told by doctors that she can't perform with the girl band until after her baby boy arrives.
Earlier today (9 September), Frankie met up with her fellow Saturdays stars - Rochelle Humes, Mollie King, Una Healy and Vanessa White - to listen to their new album Living For The Weekend.
However, she then felt a pang when she waved them off to their rehearsals afterwards.
Taking to Twitter, the star told her fans: "Sad seeing all the girls go off to rehearsals and I'm going home! Feel like the kid that wants to be part of the cool crowd! Hahaha."
Meanwhile, Frankie - who is engaged to footballer Wayne Bridge - has been going through old pictures of herself as a child while at home during her maternity leave.
Sharing one cute snap with her followers, Frankie joked about her male classmate who is sporting a similar haircut to the one she has today!
"Hello little me! Liam to my left was well ahead of the times with the Frankie cut!" she commented. Hehe!
Check out Frankie's maternity style in our gallery:
Copyright: Twitter The Saturdays