Wait between treatments - is this right?

Long one! I had lumpectomy on 5 March after having had 12 weeks Paclitaxel. I saw the oncologist on 23 March, when I was told I would need 14 rounds of Kadcyla. This was a bit of a shock as I expected to finish treatment with radiotherapy. The clinic letter stated I would be seen by the oncologist in 6 weeks after completing radiotherapy and received an appointment for 28 April. Radiotherapy starts on Friday 25 April for 5 sessions. The appointment with the oncologist was cancelled as I would be having radiotherapy that day and I was told it would be rescheduled. I heard nothing so I called today and was told I would have an appointment 6 weeks after radiotherapy finishes. That doesn’t seem right to me, I want to know if and when I will be having Kadcyla, I get different messages from different clinicians and just want some clarity, my life is on hold until I know what happens next. I’m really quite upset about it, especially the ‘relaxed’ attitude of the person on the phone this morning. I know there will be a gap between finishing radiotherapy and starting Kadcyla but don’t know why I have to wait 6 weeks to see the oncologist, I have so many questions!