The mild itchiness might clear up in a couple days. You probably attempted sex way too soon, though. Yeast infections can reaaaally dry you out, and you have to give it time. A week of pelvic rest is not a bad idea.
Yeast infections rarely cause further problems. You're not going to get Pelvic Inflammatory Disease from a yeast infection. Your vagina ALWAYS has yeast in it. It's when it grows over that the infection happens. If it really could cause that problem, women would be in a lot worse shape, way more often. A lot of times the body can even correct the imbalance of yeast on its own! (I don't recommend using that approach, though.)
I'd say if it isn't better by Monday, and since the first OTC treatment didn't work, go to your GYN. It could be that the strain of yeast is different from what the OTC treats, the OTC wasn't strong enough, etc.