@OP:
Hey man, one C will definitely not hurt you. You're a junior and you've been getting all A's and one B so far. So with that C factored in, your GPA sounds like it's still around a 3.5 or so. Just like the people above have been saying, try to look at the big picture. Unless you're a crazy gunner and are absolutely adamant about getting into like a top medical school, your grades shouldn't worry you so much. Everything will work out as long as you don't give up. I haven't heard a story yet about someone persevering and not becoming a doctor. As long as you've got the heart, you'll for sure become a doctor and get into a medical school. And there's no such thing as a terrible medical school... (I think 🙂 )
@FindingNismo:
Again, a couple Cs will go unnoticed for the most part. You might get asked about them during interviews, so just have your reasons ready. If you get A's and Bs for the last two years in college, you'll be golden man.
And if you still have a 3.6 after those two Cs then wow yeah, you shouldn't be worrying haha. A 3.6 is solid as heck, you don't need a 4.0 to get into med school, that's a common myth. Anyway, you'll be fine, just don't agonize and move on and do better in your remaining science classes!