I'm kind of a Clomid vet since I was on it almost a year, so I hope you can find some of this useful.

First Clomid has a loooong half life of 5-7 days. This means that it takes 5-7 days after your dose for half of it to leave your system. For all of it to leave your system it can take 6+ weeks. You can have symptoms all of that time, but I've found that they get better as the month goes on. So I might have really bad hot flashes, migraines, mood swings, etc the first week or two but after that they aren't as intense. Some people have also found that if you take it for several months and let it build up in your system some, when you stop taking it you can still see the positive effects for another cycle or two. But this also means if you take it several cycles in a row your side effects might be increased each time.
The side effects I had with clomid are nausea, dizziness, hot flashes, mood swings, migraines, and thick cervical mucus. Some of these got to be bad enough right after taking it that we couldn't BD as much as we would like at the beginning of my cycle. The thick CM was especially a problem as without good quality fertile CM the sperm are unable to reach the egg. There is however ways to combat that, such as taking EPO. I had great success with EPO so I would recommend that if you notice this problem.
Like zonee said, typically you will ovulate 5-10 days after your last pill. I took mine CD5-9 and usually ovulated CD20 so mine was a bit past that. If it gets to be too much later than that though there is a good chance you did not respond.
I would recommend temping if you aren't already, unless you are being monitored via ultrasound by your doctor. That's really the only way you can confirm which day you ovulated. It is possible to get positive OPKs but not actually ovulate.
Good luck! Hope it only takes this once!