Well, it would be pretty damn early for those side effects to be from a pregnancy. I think it takes about a week for the egg to even implant, so you should not be feeling pregnancy symptoms right now.
You can expect a pregnancy test to be quite accurate 19 days after the unprotected sex.
Emergency contraceptive, unfortunately, works primarily by delaying ovulation. So if you had already ovulated when you had sex or before you took the pill, it probably wasn't much help. But if you hadn't yet, then that's good. And really unless you are taking your basal body temp, it's impossible to know for sure whether you had ovulated or not. Anyway, I would definitely take a test if your period doesn't come, but don't worry TOO much in the mean time.
no subject
You can expect a pregnancy test to be quite accurate 19 days after the unprotected sex.
Emergency contraceptive, unfortunately, works primarily by delaying ovulation. So if you had already ovulated when you had sex or before you took the pill, it probably wasn't much help. But if you hadn't yet, then that's good. And really unless you are taking your basal body temp, it's impossible to know for sure whether you had ovulated or not. Anyway, I would definitely take a test if your period doesn't come, but don't worry TOO much in the mean time.