How bad is a B+ in IB Math HL?

<p>Alright, so I'm in a tough situation right now. I'm a junior in my second semester of IB Math HL Y1. I had a 4.0 last semester, and I'm rocking straight A's this semester too... except math. I have an 89.9 (A-), and 89.5 is the cutoff, so I'm hanging onto that A- for dear life. Thing is, I have my final exam tomorrow, and the exam is so freaking hard that I'm pretty much guaranteed to walk away this year with a B+. I know that ain't bad, especially since it's an IB HL course, but three things I'm worried about:</p>

<ol>
<li><p>My GPA will drop from a 4.0 to a 3.8883. Still great, but it shows that I peaked early and dropped off.</p></li>
<li><p>Second semester junior year is the worst possible time for your grades to dip.</p></li>
<li><p>I have my targets set on the Wharton school at Penn, and from what I've heard, Ivy League schools don't like B+'s. At all.</p></li>
</ol>

<p>So my question is, how bad REALLY is a B+ in an advanced course like Math HL, and how will it affect my chances of getting into Wharton?</p>

<p>P.S. This ain't Comedy Central, so please no sarcastic answers.</p>