what to do

Lately Everytime me and my bf have sex i have the urge to pee and i heard thats a feeling of squirting and since im pregnant i feel everything more ! So now the feeling is there everytime he strokes inside & it gets annoying sometimes . And he wont stop going in until i squirt but i just cant and it annoys me . I try letting go but nothing happens . Does anyone know how can i finally do this ? Has anyone else experienced this ?