A 33 y g3p2 known to have controlled essential hypertion on propranolol and hydrochlorothiazide is pregnant in 6 weeks of g.a should we change meds?

Yes: I would stop the hydrochlorthiazide as in pregnancy blood volume should rise and hctz (hydrochlorothiazide) prevents that. You could continue propanolol alone for now. The normal drop in BP in pregnancy may maintain your BP in the normal range initially. As your BP is followed, you could raise the dose of propanolol or add another drug only if BP rises >160/100.