I can tell you are starting to panic and there really is no need. I reckon looking at your monitor readings that you are quite likely to have ovulated later than the 17th. That high temp on the 16th is a puzzle to me as it doesn't show 6 lower temps than the last one at ovulation time (accordingly to the present red cross lines). Still, at least it is giving you an idea. Even if you did ovulate when the graph says so, you still have a good BD time of 3 days beforehand, which means you are in with a chance no matter which day is correct. Little swimmers can last for up to 3 days of average, so don't fret too much.
If you think about it, there are millions of people who get the timing exactly right and they still don't succeed in getting pregnant. When the time is right for you, it will happen. You've done your best and still have as good a chance as anyone.
Try to take it easy and consider yourself hugged.
