No, Monica was not pregnant at the end of Friends.
The final episode of Friends, “The Last One”, aired on May 6, 2004. In this episode, Monica and Chandler adopt twins, a boy and a girl, named Jack and Erica. However, Monica is not pregnant at any point during the episode or the show’s entire 10-season run.
There was some speculation about whether or not Monica would become pregnant in the show’s final season. This was due in part to Courteney Cox, the actress who played Monica, becoming pregnant in real life during the filming of the show’s final season. However, the show’s writers did not incorporate Cox’s pregnancy into the storyline, and Monica remained childless until the adoption of Jack and Erica.
It’s worth noting that Friends tackled a number of important issues related to pregnancy and parenthood over the course of its run. For example, the character of Phoebe carried her brother’s triplets as a surrogate, and Rachel became a single mother to her daughter Emma. The show also explored themes related to infertility and the challenges of becoming a parent.
In conclusion, Monica was not pregnant at the end of Friends. While there was some speculation about whether or not she would become pregnant in the show’s final season, the writers ultimately chose to have Monica and Chandler adopt twins instead.