AP classes for next year!! advices? (physics, bio)

<p>I'm going to be a senior next year and I'm planning to take about 4 AP classes..</p>

<p>I'm going to be taking AP Calc for sure and I'm also considering about taking AP physics B..
but I heard a lot of people have some difficutlies in physics..
Do you guys think Physics B is harder than Calculus? Should i sign up for physics too??</p>

<p>I'm also taking AP Bio class next year, but I want to take the SAT Bio subject test in Nov..
so I'm planning to self-study the subject during summer. what are your opinions on this? anybody did self-study for ap bio??</p>