Will i bug my doctor if...?

It really depends on the HMO in particular and their turn around time for authorization. If the orthopedist is authorized to write referrals, it should take no longer than a day or two. If they have to go back to your primary care physician, it could take at least a week. Sometimes even after getting back to the PCP, the HMO may have it's own review process. If it's not there by Monday, I would give them a call, but I've waited up to two weeks for some of my patients to get referrals.