No sex before HSG?

Li
My RE uses an outside radiologist to perform HSG and gave me the phone number to call them once I started AF. Well my SO and I had sex CD28 and about four hours later I started spotting. AF came in on time the following morning after sex. The radiologist refused to do the HSG because they count that as having sex once AF started....I guess the spotting 4 hours after sex. I called my RE and told them what happened. They hadn't said anything about not having sex once AF started anyway. Anyway apparently they didn't know about this protocol. Has anyone else heard of this?