Please answers.. Child has fever.. Doc appt in the morning?

My 10 month old has had a mild fever for 2 days now... I've given her Tylenol and seems to make it drop a bit but it alwaysgoes right back up when it wears off... I just checked her again and it was 102.2 under the arm and i'm pretty sure ur suppose to add a degree when it's taken under the arm so tht would make it 103.2.... She has a doc appt in the morning but i'm worried bc i know high fevers can cause seizures... Do i wait it out and just keep a close check on it or go ahead and take her to the ER..? She isnt even acting sick what so ever... At first i thought her mild fever was associated with her cutting her second tooth but i know teething does not cause high fever and hers seems to get higher and higher... She's playful aside from acting a little weak but she isnt acting any different thn usual... Just need some advice please!! Wht is the best thing to do in this situation.. Of course this is my first child so every little thing worries me.. :(