Hi runnermum, yeah maybe would be good idea to check. My FS definitely doesnt ban sex, but with the stimulated cycles you dont really feel like it anyway. But with FET, im sure it'd be ok, because you dont have the t/f until way after you ovulate- not sure if you have blasties or not. My FS told me that one of his patients had twins- and he is pretty sure one is from the t/f and thought maybe one from BD'ing. All FS are diff, so maybe just check with yours. Dont worry so much if you already have though LOL, cant change it now!!!