My OB suggested the same thing with my clomid cycles, it seems to help. If you don't like the taste of Robitussin or would rather just take a pill mucinex is the same thing. That's what I've done in the past and will do again cause I have the worst time getting Robitussin down...blech. Either way you still have to be sure to drink plenty of water for it to really be effective. Good luck!
sorry, i didn't read your response before i posted mine...ditto what you said!