Side effects

I actually had some side effects last evening. They're worth mentioning just because I've had so few.
Yesterday was both chemo and radiation. When I met with the doctor, he asked the usual questions about pain, nausea, flu-like symptoms, and I brushed them away.
In the evening, during yoga class, I suddenly felt nausea, which I thought at first was due to the backbends; but it was a Restorative class, which meant that the backbends were very gentle, and besides, I usually don't have trouble with my back. Then I started feeling cold and I spent the rest of the class shivering under two blankets. By the time I got home I had all the rest of the symptoms the doctor had asked me about. Clearly they were due to the combination of therapies.
Jerry took care of me, bringing me pills and blankets, and by this morning I was feeling much better. Now I'm fine again, with two main reactions:
First, of course, is that I'm more appreciative of how well I've been doing so far.
The other is almost relief. If I got sick, the cancer must really be in bad shape. There's a medication for pancreatic cancer that I've read about on a pc forum. A common side effect of it, and indication that it's working, is major acne. A woman wrote in despairingly that she'd been on this medication for two weeks and her skin was still clear. Everyone else wrote back to say that the side effects weren't absolutely necessary. The medication could still be working fine, but she said that she couldn't believe it. She needed the skin breakouts to convince herself that she was getting the full benefit of the chemo. When I read it, my first reaction was that she should consider herself lucky to have missed out on yet one more misery, but after last night I understand her better.
If I feel too well, something is wrong? That's just plain weird. I need to think about this some more.