Hi Johjoh,
Firstly, congrats to you for finishing chemo. Such a lovely feeling knowing that you don't have to do that again. And yes, the same happened to me. I think your veins just decide they have had enough and don't want to play anymore! Go and see your gp. I also think you could ring your oncologists rooms and speak to someone there. I'm sure you can see them anytime if you have concerns. Radiation is tiring because it's daily. It all gets a bit tedious. Do you have access to a breast care nurse? They can be helpful also.
Love & hugs,
Paula xxx