Yes, but not without a bit of hesitation. Let me explain.
First and foremost, birth control pills should be available over the counter. That would be much more useful. I really do not understand why they're not - I've heard the arguments against this, but it's not that hard to mandate a brief meeting with a pharmacist about the risks when getting it or something. There are a ton of more dangerous things that are over the counter. If the Pill becomes over the counter, then Plan B should be too.
However, my fear with Plan B being over the counter and the Pill not is that women will start using Plan B as their main source of birth control. In the USSR, where birth control wasn't common, women used abortions as a primary form of birth control, and, though I'm pro-choice, I still feel bad simply thinking about how many of those abortions could have been prevented with ample birth control. Condoms break and some men hate wearing them (because they've been told so many times that it "feels bad" that it becomes fact) and the Pill is prescription only and sometimes a woman can't afford to go to the gyno or doesn't have health insurance, so she doesn't have the pill, so they might just have unprotected sex and use Plan B later.
Some birth control pills are incredibly cheap - I get the one I'm on for $21 for a 3 month supply because I paid $5 to join a grocery store's pharmacy club and it's on sale (compared to over $60 for the same exact pill, same brand too, elsewhere). However, people can't get them because gynos can be expensive, especially if your insurance is bad or missing. The Pill really should be over the counter first, and then followed by Plan B.
I think that all forms of birth control should be accessible to anyone of any age. Sex is absolutely unpreventable no matter how many people enforce abstinence and such. The most that one can do is educate others on the risks of sex and provide them easy access to protection. Babies should not be planned not accidents, and it is a woman's right to decide if she wants a child not be forced to have them because there's no option available. Besides without these sorts of controls people do at times decide on much more dangerous options...