I don't belong here

I started taking Warfarin last Thursday. I have to take 5 little brown tablets, every day at 6pm. I'm monitored quite closely and will go to anticoagulent clinic twice a week at first and then once per week until I get the cardioversion done. On each session, they take blood and measure it's INR value - basically, how the blood clots. People not taking warfarin have INR of around 1. Before I get zapped, I need to have a stable INR of 2.5 for a period of 4 weeks. I've taken 4 days worth of tablets and I've now gone from 1 to 1.3. Everyone reacts differently to warfarin so it's impossible to know how long it's going to take to stabilise at 2.5.
What struck me at the clinic today was that I was by far the youngest person there - by a long way. There were no children apart from my own but there was a little wendy house and a stack of books - they were noticeably immaculate and obviously hadn't been used by many kids. I felt that we were a bit out of place really.
So far no side effects although I'm doing my best to talk myself into them. I had a splitting headache on my ride yesterday and I started worrying that I was about to have a stroke (a problem associated with my condition). A more likely explanation is that I ate and drank very little prior to my ride yesterday and was probably just a bit dehydrated.

7 1/2 hours of riding last week - good going.