How will 3 "B"s affect my chances.

<p>So I am applying to a bunch of top level colleges, and I had an almost 4.0 before. I took all of the hardest classes at my school, went full IB... I even took extra 7th period classes each year.
This semester I received three Bs, two B+s in IB Bio and IB English, and one B in Calc BC. My aunt died the week of finals, and there was a lot of stress in my home. I am explaining this to the colleges, but the grades will show on my mid-year report.
I am Hispanic and got a 2240 on my SAT. I also have fairly strong ec.s
I know that they won't help my chances, but how much will they hurt them? any suggestions on other things I can do?
Oh, I also go to a pretty low ranked public school, and I am a NHMS, URM, and I passed all of my AP tests with a 4 average, 2 3s and 1 5. All of the rest were 4s.</p>